=927. Edaphic plant societies.=—These are equivalent to edaphic

plant formations, and the vegetation is of course controlled by the

peculiar conditions of the soil. There are a number of different

kinds of edaphic plant societies determined by the character of the

physiographic areas. 1st. _Sphagnum moors._ These are formed in shallow

basins originally with more or less water. The growth of the sphagnum

moss along with other vegetation and its partial decay in the water

builds up ground rapidly so that in course of time the pond may be

completely filled in. This filling in proceeds from the shore toward

the center, and in the early stages of course there would be a pond

in the center. The partial decay of vegetation creates an excess of

humus acid which retards absorption by the roots. The conditions are

such, then, as require aerial structures for retarding the loss of

water, and plants growing in such moors are usually xerophytes. Some of

the plants are identical with those growing in the arctic tundra. 2d.

_Sand_[53] _strand of beach._ The quantity of sand with very little or

no admixture of humus or plant food makes it difficult for plants to

obtain a sufficient amount of water even where rainfall is abundant.

The same may be said of the sand dunes farther back from the shore. The

plants of these areas are then usually xerophytes. Some of the plants

accustomed to growing in such localities are American sea-rocket,

seaside spurge, bugseed, sea-blite, sea-purslane, the sandcherry, dwarf

willow, marram-grass, certain species of beard-grass, etc. 3d. _Rocky

shores or areas._ Here lichens and mosses first grow, later to be

followed by herbs, grasses, shrubs, and trees, as decayed plant remains

accumulate in the rock crevices. 4th. _Shores of ponds, or swamp

moors._ Here the vegetation often takes on a zonal arrangement if the

ground gradually slopes to the shore and out into the pond. In Fig. 493

is shown zonal distribution of plants. The different kinds of plants

are drawn into these zones by the varying amount of ground water in

the soil, or the varying depth of the water on the margin of the pond

as one proceeds from the land towards the deeper water. On the border

lines or tension lines between the different zones the plants are

struggling to occupy here ground which is suitable for each adjacent

individual formation. Other edaphic societies are those of marl ponds,

alkaline areas, oases in deserts, warm oases in arctic lands, the

forested areas along river bottoms in prairie or plains regions, etc.

[Illustration: Fig. 493. Macrophytes in the upper zone of the photic

region. Ascophyllum and Fucus at low tide, Hunter’s Island, New York

City. (Photograph by M. A. Howe.)]

[Illustration: Fig. 494.

Zonal distribution of plants, South Shore, Cayuga Lake.]

=928. Aquatic plant societies.=—In general we might distinguish

three kinds, 1st. _Fresh-water plant societies_, with floating algæ

like spirogyra, œdogonium, etc., the floating duck-meats, riccias; the

plants of the lily type with roots and stems attached to the bottom

and leaves floating on the surface, like the water-lily and certain

pondweeds, and finally the completely submerged ones like certain

pondweeds, the bassweed (Chara), etc. 2d. _Marine plant societies_,

which are made up mostly of the red and brown algæ or “seaweeds,”

though some green algæ and flowering plants also occur. 3d. _The salt

marshes_ where the water is brackish and there is usually a luxuriant

growth of marsh-grasses.

FOOTNOTES:

[47] For a fuller discussion of this subject by the author see Chapters

XLVI-LVII of his “College Text-book of Botany” (Henry Holt & Co.).

[48] =οῖκος= = house, and =λόγος= = discourse.

[49] Term used by Schimper.

[50] See the author’s “College Text-book of Botany.” Chapter XLIX.

[51] =ἔδαφος= = ground.

[52] For a full discussion of forest societies see Chapter L in the

author’s “College Text-book of Botany.”

[53] See Chapter LIV of the author’s “College Text-book of Botany.”

CHAPTER XLVII.

CLASSIFICATION OF THE ANGIOSPERMS.

Relation of Species, Genus, Family, Order, etc.

=929. Species.=—It is not necessary for one to be a botanist in

order to recognize, during a stroll in the woods where the trillium

is flowering, that there are many individual plants very like each

other. They may vary in size, and the parts may differ a little in

form. When the flowers first open they are usually white, and in age

they generally become pinkish. In some individuals they are pinkish

when they first open. Even with these variations, which are trifling

in comparison with the points of close agreement, we recognize the

individuals to be of the _same kind_, just as we recognize the corn

plants, grown from the seed of an ear of corn, as of the same kind.

Individuals of the same kind, in this sense, form a _species_. The

white wake-robin, then, is a species.

But there are other trilliums which differ greatly from this one. The

purple trillium (T. erectum) shown in fig. 495 is very different from

it. So are a number of others. But the purple trillium is a species. It

is made up of individuals variable, yet very like one another, more so

than any one of them is like the white wake-robin.

=930. Genus.=—Yet if we study all parts of the plant, the

perennial rootstock, the annual shoot, and the parts of the flower, we

find a great resemblance. In this respect we find that there are

several species which possess the same general characters. In other

words, there is a relationship between these different species, a

relationship which includes more than the individuals of one kind. It

includes several kinds. Obviously, then, this is a relationship with

broader limits, and of a higher grade, than that of the individuals

of a species. The grade next higher than species we call _genus_.

Trillium, then, is a genus. Briefly the characters of the genus

trillium are as follows:

[Illustration: Fig. 495. Trillium erectum (purple form), two plants

from one rootstock.]

=931. Genus trillium.=—Perianth of six parts: sepals 3,

herbaceous, persistent; petals colored. Stamens 6 (in two whorls),

anthers opening inward. Ovary 3-loculed, 3-6-angled; stigmas 3,

slender, spreading. Herbs with a stout perennial rootstock, with

fleshy, scale-like leaves, from which the low annual shoot arises,

bearing a terminal flower and 3 large netted-veined leaves in a whorl.

_Note._—In speaking of the genus the present usage

is to say trillium, but two words are usually employed

in speaking of the species, as Trillium grandiflorum,

T. erectum, etc.

=932. Genus erythronium.=—The yellow adder-tongue, or dogtooth

violet (Erythronium americanum), shown in fig. 496, is quite different

from any species of trillium. It differs more from any of the species

of trillium than they do from each other. The perianth is of six parts,

light yellow, often spotted near the base. Stamens are 6. The ovary is

obovate, tapering at the base, 3-valved, seeds rather numerous, and the

style is elongated. The flower stem, or scape, arises from a scaly bulb

deep in the soil, and is sheathed by two elliptical-lanceolate, mottled

leaves. The smaller plants have no flower and but one leaf, while the

bulb is nearer the surface. Each year new bulbs are formed at the end

of runners from a parent bulb. These runners penetrate each year deeper

into the soil. The deeper bulbs bear the flower stems.

=933. Genus lilium.=—While the lily differs from either the

trillium or erythronium, yet we recognize a relationship when we

compare the perianth of six colored parts, the 6 stamens, and the

3-sided and long 3-loculed ovary.

[Illustration: Fig. 496. Adder-tongue (erythronium). At left below

pistil, and three stamens opposite three parts of the perianth. Bulb at

the right.]

=934. Family Liliaceæ.=—The relationship between genera, as

between trillium, erythronium, and lilium, brings us to a still higher

order of relationship, where the limits are broader than in the genus.

Genera which are thus related make up the _family_. In the case of

these genera the family has been named after the lily, and is the lily

family, or _Liliaceæ_.

=935. Order, class, group.=—In like manner the lily family, the

iris family, the amaryllis family, and others which show characters of

close relationship are united into an _order_ which has broader limits

than the family. This order is the lily order, or order _Liliales_. The

various orders unite to make up the _class_, and the classes unite to

form a _group_.

=936. Variations in usage of the terms class, order, etc.=—Thus,

according to the system of classification adopted by some, the

angiosperms form a _group_. The group angiosperms is then divided into

two _classes_, the _monocotyledones_ and _dicotyledones_. (It should

be remembered that all systematists do not agree in assigning the

same grade and limits to the classes, subclasses, etc. For example,

some treat of the angiosperms as a class, and the monocotyledons

and dicotyledons as subclasses; while others would divide the

monocotyledons and dicotyledons into classes, instead of treating each

one as a class or as a subclass. Systematists differ also in usage as

to the termination of the ordinal name; for example, some use the word

_Liliales_ for _Liliifloræ_, in writing of the order.)

[Illustration: Fig. 497.

_A._ Cross-section of the stem of an oak tree thirty-seven years old,

showing the annual rings. _rm_, the medullary rays; _m_, the pith

(medulla). _B._ Cross-section of the stem of a palm tree, showing the

scattered bundles.]

=937. Monocotyledones.=—In the monocotyledons there is a single

cotyledon on the embryo; the leaves are parallel-veined; the parts

of the flower are usually in threes; endosperm is usually present in

the seed; the vascular bundles are usually closed, and are scattered

irregularly through the stem as shown by a cross-section of the stem

of a palm (fig. 497), or by the arrangement of the bundles in the corn

stem (fig. 57). Thus a single character is not sufficient to show

relationship in the class (nor is it in orders, nor in many of the

lower grades), but one must use the sum of several important characters.

=938. Dicotyledones.=—In the dicotyledons there are two

cotyledons on the embryo; the venation of the leaves is reticulate;

the endosperm is usually absent in the seed; the parts of the flower

are frequently in fives; the vascular bundles of the stem are

generally open and arranged in rings around the stem, as shown in the

cross-section of the oak (fig. 497). There are exceptions to all the

above characters, and the sum of the characters must be considered,

just as in the case of the monocotyledons.

=939. Taxonomy.=—This grouping of plants into species, genera,

families, etc., according to characters and relationships is

_classification_, or _taxonomy_.

To take Trillium grandiflorum for example, its position in the system,

if all the principal subdivisions should be included in the outline,

would be indicated as follows:

Group, Angiosperms.

Class, Monocotyledones.

Order, Liliales.

Family, Liliaceæ.

Genus, Trillium.

Species, grandiflorum.

In the same way the position of the toothwort would be indicated as

follows:

Group, Angiosperms.

Class, Dicotyledones.

Order, Papaverales.

Family, Cruciferæ.

Genus, Dentaria.

Species, diphylla.

But in giving the technical name of the plant only two of these names

are used, the genus and species, so that for the toothwort we say

_Dentaria diphylla_, and for the white wake-robin we say _Trillium

grandiflorum_.

=940. Kingdom and Subkingdom.=—Organic beings form altogether two

kingdoms, the Animal Kingdom and the Plant Kingdom. The Plant Kingdom

is then divided into a number of subkingdoms as follows: 1st,

Subkingdom Thallophyta, the thallus plants, including the Algæ and

Fungi; 2d, Subkingdom Bryophyta, the moss-like plants, including the

Liverworts and Mosses; 3d, Subkingdom Pteridophyta, the fern-like

plants, including Ferns, Lycopods, Equisetum, Isoetes, etc.; 4th,

Subkingdom Spermatophyta, the seed plants, including Gymnosperms and

Angiosperms. Subkingdoms are divided into groups of lower order down to

the classes. So there are subclasses, subfamilies or tribes, subgenera,

and even subspecies. But taking the principal taxonomic divisions from

the greater to the lesser rank, the order would be as follows:

Plant Kingdom.

Subkingdom, Spermatophyta.

Group (not used in a definite sense).

Class, Gymnospermæ.

Order, Pinales.

Family, Pinaceæ.

Genus, Pinus.

Species, strobus, or, in full,

Pinus strobus, the white pine.

Group Angiospermæ.

I. CLASS MONOCOTYLEDONES.

=941. Order Pandanales.=—Aquatic or marsh plants. The cattail

flags (Typha) and the bur-reeds (Sparganium), each representing a

family. The name of the order is taken from the tropical genus Pandanus

(the screw-pine often grown in greenhouses).

=942. Order Naiadales.=—Aquatic or marsh herbs. Three families

are mentioned here.

The pondweed family (Naiadaceæ), named after one genus, Naias. The

largest genus is Potamogeton, the species of which are known as

pondweeds. Ruppia occidentalis occurs in saline ponds in Nebraska, and

R. maritima along the seacoast and in saline districts in the interior.

The water-plantain family (Alismaceæ) includes the water-plantain

(Alisma) and the arrow-leaves (Sagittaria).

The tape-grass family (Vallisneriaceæ) includes the tape-grass, or

eel-grass (the curious Vallisneria spiralis).

=943. Order Graminales.=—Two families.

The grass family (Gramineæ), the grasses and grains.

The sedge family (Cyperaceæ), the sedges.

=944. Order Palmales=, with one family, Palmaceæ, includes the

palms, abundant in the tropics and extending into Florida. Cultivated

in greenhouses.

=945. Order Arales.=

The arum family (Araceæ). Flowers in a fleshy spadix. Examples: Indian

turnip (Arisæma), sweet-flag (Acorus), skunk-cabbage (Spathyema).

The duckweed family (Lemnaceæ). (Examples: Lemna, Spirodela, Wolffia.

See paragraphs 51-53.)

=946. Order Xyridales=, from the genus Xyris, the yellow-eyed

grass family (Xyridaceæ). Species mostly tropical, but a few in North

America. Other examples are the pipewort family (Eriocaulaceæ, example,

Eriocaulon septangulare), the pineapple family (Bromeliaceæ, example,

the pineapple cultivated in Florida); the Florida moss or hanging moss

(Tillandsia usneoides); the spiderwort family (Commelinaceæ), including

the spiderwort (Tradescantia, several species in North America); the

pickerel-weed family (Pontederiaceæ), including the genus Pontederia in

borders of ponds and streams.

=947. Order Liliales.=—Some of the families are as follows:

The rush family (Juncaceæ, example, Juncus), with many species, plants

of usually swamp habit.

The lily family (Liliaceæ, examples: Lilium, Allium = Onion,

Erythronium, Yucca).

The iris family (Iridaceæ, examples: Iris, the blue-flag, fleur-de-lis,

etc.).

The lily-of-the-valley family (Convallariaceæ, examples:

lily-of-the-valley, Trillium, etc.)

The amaryllis family (Amaryllidaceæ, examples: Narcissus, the daffodil;

Cooperia, in southwestern United States).

=948. Order Scitaminales.=—This order includes the large showy

cultivated Canna of the canna family.

=949. Order Orchidales.= Example, the orchid family (Orchidaceæ)

with Cypripedium, Orchis, etc.

II. CLASS DICOTYLEDONES.

SERIES 1. CHORIPETALÆ. Petals wanting (Apetalæ, or

Archichlamydæ of some authors), or present and distinct from one

another (Polypetalæ, or Metachlamydæ).

=950. Order Casuarinales=, confined to tropical seacoasts

(example, Casuarina).

=951. Order Piperales= includes the lizard’s-tail family

(Saururaceæ), Saururus cernuus, lizard’s-tail, in the eastern United

States.

=952. Order Salicales.=—Shrubs or trees, flowers in aments.

Includes the willows and poplars (Salix and Populus of the willow

family, Salicaceæ).

=953. Order Myricales.=—Shrubs or small trees. Includes the

sweet-gale (Myrica gale) in wet places in northern United States and

British North America, Myrica cerifera forming thickets on sand dunes

along the Atlantic coast, and the sweet-fern (Comptonia peregrina = C.

asplenifolia) in the eastern United States in dry soil of hillsides.

=954. Order Leitneriales.=—Shrubs or trees. Includes the

cork-wood, Leitneria floridana (Leitneriaceæ).

=955. Order Juglandales.=—Trees, staminate flowers in aments. The

walnut family (Juglandaceæ, examples: walnut, butternut, etc. Juglans;

hickory, Hicoria = Carya).

=956. Order Fagales.=—Trees and shrubs. Flowers in aments, or the

pistillate ones with an involucre which forms a cup in fruit, as in the

acorn of the oak.

The birch family (Betulaceæ, examples: Betula, birch; Corylus,

hazelnut; Alnus, alder, etc.).

The beech family (Fagaceæ = Cupuliferæ, examples: Fagus, beech;

Castanea, chestnut; Quercus, oak).

=957. Order Urticales.=—Trees, shrubs, or herbs. Examples: the

elm family (Ulmaceæ), the mulberry family (Moraceæ), and the nettle

family (Urticaceæ).

=958. Order Santalales=, herbs or shrubs, mostly parasitic.

The mistletoe family (Loranthaceæ), with the American mistletoe

(Phoradendron flavescens), parasitic on deciduous trees in the South

Atlantic, Central, and Gulf States (N. J. to Ind. Ter.).

The sandalwood family (Santalaceæ, example, the bastard toad-flax,

Comandra umbellata), widely distributed in North America.

=959. Order Aristolochiales.=—Herbs or vines with heart-shaped or

kidney-shaped leaves. The birthwort family (Aristolochiaceæ, example,

Aristolochia serpentaria, the Virginia snake-root, eastern United

States; wild ginger, or heart-leaf, Asarum canadense, eastern North

America.)

=960. Order Polygonales.=—Examples: the buckwheat family

(Polygonaceæ), including buckwheat (Fagopyrum), and numerous species

of Polygonum, known as smartweed, water-pepper, tear-thumb, bindweed,

knotweed, prince’s-feather, etc.

=961. Order Chenopodiales.=—Herbs. There are several families;

one of the largest is the goosefoot family (Chenopodiaceæ). The genus

Chenopodium includes many species, known as goosefoot, lamb’s-quarters,

etc. Here belong also the Russian thistle (Salsola tragus) and the

saltwort (S. kali). The former is sometimes a troublesome weed in the

central and western United States, naturalized from Europe. The latter

occurs along the Atlantic coast on seabeaches. Atriplex occurs in salty

or alkaline soil, also the glasswort (Salicornia herbacea), the bugseed

(Corispermum). The pokeweed family (Phytolaccaceæ), the Amaranth family

(Amaranthaceæ), the purslane family (Portulacaceæ, including the

purslane or “pursley,” Portulaca oleracea, and the spring-beauty,

Claytonia virginica), and the pink family (Caryophyllaceæ), belong here.

=962. Order Ranales.=—Herbs, shrubs, or trees. Examples are:

The water-lily family (Nymphæaceæ), with the yellow water-lily (Nymphæa

advena = Nuphar advena) and the white water-lily (Castalia odorata =

Nymphæa odorata).

The magnolia family (Magnoliaceæ), including the magnolias

(Magnolia) and the tulip-tree (Liriodendron). The crowfoot family

(Ranunculaceæ), with the buttercups, hepatica, clematis, etc.

=963. Order Papaverales.=—Mostly herbs. Examples are:

The poppy family (Papaveraceæ), including the opium or garden poppy

(Papaver somniferum), the blood-root (Sanguinaria canadensis), the

Dutchman’s-breeches (Bicuculla cucullaria = Dicentra cucullaria),

squirrel’s-corn (Bicuculla canadensis = D. canadensis).

The mustard family (Cruciferæ), including the toothwort (Dentaria),

shepherd’s-purse (Bursa bursa-pastoris = Capsella bursa-pastoris), the

cabbage, turnip, etc.

=964. Order Sarraceniales.=—Insectivorous plants.

The pitcher-plant family (Sarraceniaceæ). Examples: Sarracenia

purpurea, the pitcher-plant, in peat-bogs, northern and eastern North

America.

The sundew family (Droseraceæ). Examples: Drosera rotundifolia, and

other sundews.

=965. Order Rosales.=—Herbs, shrubs or trees. Seventeen families

are given in the eastern United States. Examples:

The riverweed family (Podostemaceæ), containing the riverweed

(Podostemon).

The saxifrage family (Saxifragaceæ), containing a number of species.

Example, Saxifraga virginiensis.

The gooseberry family (Grossulariaceæ), including the wild and the

cultivated gooseberry.

The witch-hazel family (Hamamelidaceæ), including the witch-hazel

(Hamamelis), in eastern North America, and the sweet gum (Liquidambar

styraciflua).

The plane-tree family (Platanaceæ), with the plane-tree, or buttonwood

(Platanus occidentalis), eastern North America. (Other species occur in

western United States.)

The rose family (Rosaceæ), including roses, spiræas, raspberries,

strawberries, the shrubby cinquefoil (Dasiphora fruticosa), etc.

The apple family (Pomaceæ), including the apple, mountain-ash, pear,

June-berry (or shadbush, also service-berry), the hawthorns (Cratægus).

The plum family (Drupaceæ), including the cherries, plums, peaches, etc.

The pea family (Papilionaceæ), including the pea, bean, clover, vetch,

lupine, etc., a very large family.

=966. Order Geraniales.=—Herbs, shrubs, or trees. Nine families

in the eastern United States. Examples:

The geranium family (Geraniaceæ), with the cranesbill (Geranium

maculatum) and others.

The wood-sorrel family (Oxalidaceæ), with the wood-sorrel (Oxalis

acetosella) and others.

The flax family (Linaceæ). Example, flax (Linum vulgaris).

The spurge family (Euphorbiaceæ). Plants with a milky juice, and

curious, degenerate flowers. Examples: the castor-oil plant (Ricinus),

the spurges (many species of Euphorbia).

=967. Order Sapindales.=—Mostly trees or shrubs. Twelve families

in the eastern United States. Example:

The sumac family (Anacardiaceæ), containing the sumacs in the genus

Rhus. Examples: the poison-ivy (R. radicans), a climbing vine, in

thickets and along fences, in eastern United States. Sometimes

trained over porches. The poison-oak (R. toxicodendron), a low shrub.

Poison-sumac or poison-alder (R. vernix = R. venenata), sometimes

called “thunderwood,” or dogwood, is a large shrub or small tree, very

poisonous. The smoke-tree (Cotinus cotinoides) belongs to the same

family, and is often planted as an ornamental tree. The maple family

(Aceraceæ), including the maples (Acer).

The buckeye family (Hippocastanaceæ), including the horse-chestnut

(Æsculus hippocastanum), much planted as a shade tree along streets.

Also there are several species of buckeye in the same genus.

The jewelweed family (Balsaminaceæ), including the touch-me-not

(Impatiens biflora and aurea) in moist places. The garden balsam (Imp.

balsamea) also belongs here.

=968. Order Rhamnales.=—Shrubs, vines, or small trees. There are

two families, the buckthorn (Rhamnaceæ), the grape family (Vitaceæ),

including the grapes (Vitis), the American ivy (Parthenocissus

quinquefolia = Ampelopsis quinquefolia), in woods and thickets, eastern

North America, and much planted as a trailer over porches. The Japanese

ivy (P. tricuspidata = A. veitchii) used as a trailer on the sides of

buildings belongs here.

=969. Order Malvales.=—Herbs, shrubs, or trees.

The linden family (Tiliaceæ). Example, the basswood or American linden

(Tilia americana.)

The mallow family (Malvaceæ), including the hollyhock, the mallows,

rose of Sharon (Hibiscus), etc.

=970. Order Parietales=, with seven families in the eastern United

States. The St. John’s wort (Hypericum) and the violets each represent

a family. The violets (Violaceæ) are well-known flowers.

=971. Order Opuntiales.=—These include the cacti (Cactaceæ),

chiefly growing in the dry or desert regions of America.

=972. Order Thymeleales=, with two families and few species.

=973. Order Myrtales.=—Land, marsh, or aquatic plants. The most

conspicuous are in the evening primrose family (Onagraceæ), including

the fireweeds, or willow herbs (Epilobium), and the evening primrose

(Onagra biennis = Œnothera biennis).

=974. Order Umbellales.=—Herbs, shrubs, or trees, flowers in

umbels.

The ginseng family (Araliaceæ). This includes the spikenards and

sarsaparillas in the genus Aralia, and the ginseng (or “sang”), Panax

quinquefolium.

The carrot family (Umbelliferæ). This family includes the wild carrot

(Daucus carota), the poison-hemlock (Cicuta), the cultivated carrot and

parsnip, and a large number of other genera and species.

The dogwood family (Cornaceæ). The flowering dogwood (Cornus florida),

abundant in eastern North America, is an example.

SERIES 2. GAMOPETALÆ (= Sympetalæ or Metachlamydæ). Petals

partly or wholly united, rarely separate or wanting.

=975. Order Ericales.=—There are six families in eastern United

States. Examples:

The wintergreen family (Pyrolaceæ), including the shin-leaf (Pyrola

elliptica).

The Indian-pipe family (Monotropaceæ), with the Indian-pipe (Monotropa

uniflora) and other humus saprophytes. (See paragraphs 182-191.)

The heath family (Ericaceæ). Examples: Labrador tea (Ledum), in bogs

and swamps in northern North America. The azaleas, with several

species widely distributed, are beautiful flowering shrubs, and many

varieties are cultivated. The rhododendrons are larger with larger

flower clusters, also beautiful flowering shrubs. R. maximum in the

Alleghany Mountains and vicinity, from Nova Scotia to Ohio and Georgia.

R. catawbiense, usually at somewhat higher elevations, Virginia to

Georgia. The mountain laurel (Kalmia latifolia) and other species rival

the rhododendrons and azaleas in beauty. The trailing arbutus (Epigæa

repens) in sandy or rocky woods is a well-known small trailing shrub

in eastern North America. The sourwood (Oxydendrum arboreum) is a tree

with white racemes of flowers in August, and scarlet leaves in autumn.

The spring or creeping wintergreen (Gaultheria procumbens) is a small

shrub with aromatic leaves, and bright red spicy berries.

The huckleberry family (Vaccinaceæ) includes the huckleberries

(example, Gaylussacia resinosa, the black or high-bush huckleberry,

eastern United States), the mountain cranberry (Vitis-Idæa vitisidæa

= Vaccinium vitisidæa) in the northern hemisphere; the bilberries and

blueberries (of genus Vaccinium); the cranberries (examples: the large

American cranberry, Oxycoccus macrocarpus and the European cranberry,

Oxycoccus oxycoccus, in cold bogs of northern North America, the latter

also in Europe and Asia).

=976. Order Primulales.=—Two families here. The primrose family

(Primulaceæ) contains the loosestrifes (Steironema), star-flower

(Trientalis), etc.

=977. Order Ebenales.=—Of the four families, the ebony family

(Ebenaceæ) contains the well-known persimmon (Diospyros virginiana) and

the storax family (Styracaceæ) with the silverbell, or snowdrop tree

(Mohrodendron carolinum).

=978. Order Gentianales.=—Herbs, shrubs, vines, or trees. Six

families in the United States.

The olive family (Oleaceæ) includes the common lilac (Syringa), the ash

trees (Fraxinus), the privet (Ligustrum).

The gentian family (Gentianaceæ) among other genera includes the

gentians (Gentiana).

The milkweed family (Asclepiadaceæ) contains plants mostly with a milky

juice. Asclepias with many species is one of the most prominent genera.

=979. Order Polemoniales.=—Mostly herbs, rarely shrubs and trees.

Fifteen families in the eastern United States.

The morning glory family (Convolvulaceæ) includes the bindweeds

(Convolvulus), the morning glory (Ipomæa), etc.

The dodder family (Cuscutaceæ) includes the dodders, or “love-vines.”

There are nearly thirty species in the United States. The stems are

slender and twine around other plants upon which they are parasitic

(see paragraph 179).

The phlox family (Polemoniaceæ). The most prominent genus is Phlox.

Over forty species occur in North America.

The borage family (Boraginaceæ) includes the heliotrope (Heliotropium),

the hound’s-tongue (Cynoglossum), the forget-me-not (Myosotis), and

others.

The vervain family (verbenaceæ) contains the verbenas.

The mint family (Labiatæ) contains the mints (Mentha), skull-cap

(Scutellaria), dead-nettles (Lamium).

The potato family (Solanaceæ) includes the ground-cherry (Physalis),

the nightshades (Solanum), the tomato (Lycopersicon), tobacco

(Nicotiana).

The figwort family (Scrophulariaceæ) includes the common mullein

(Verbascum), the monkey-flower (Mimulus), the toad-flax (Linaria),

turtle’s-head (Chelone), and many other genera and species.

The bladderwort family (Lentibulariaceæ) includes the curious bog or

aquatic plants with finely dissected leaves, and with bladders in which

insects are caught (Utricularia).

The trumpet-creeper family (Bignoniaceæ) includes the trumpet-creeper

(Bignonia), the catalpa tree, and others.

=980. Order Plantaginales= with one family (Plantaginaceæ)

includes the plantains (Plantago).

=981. Order Rubiales= with three families is represented by the

madder family (Rubiaceæ) with the bluets (Houstonia), the button-bush

(Cephalanthus), the partridge-berry (Mitchella), the bedstraws

(Galium), etc.

The honeysuckle family (Caprifoliaceæ) with the elder (Sambucus), the

arrowwoods and cranberry trees (Viburnum), the honeysuckles (Lonicera),

etc.

=982. Order Valerianales= with two families includes the teasel

family (Dipsacaceæ). Example, Fuller’s teasel (Dipsacus).

=983. Order Campanulales= with five families, the corolla usually

gamopetalous.

The gourd family (Cucurbitaceæ) includes the pumpkin, squash, melon,

and a few feral species. Example, the star-cucumber (Sicyos angulatus),

in moist places in eastern and middle United States.

The bell-flower family (Campanulaceæ) includes the hare-bells or

bell-flowers (Campanula), the lobelias (example, Lobelia cardinalis,

the cardinal-flower), etc.

The chicory family (Cichoriaceæ) includes the chicory or succory

(Cichorium intybus, known also as blue-sailors), the oyster-plant or

salsify (Tragopogon porrifolius), the dandelion (Taraxacum taraxacum =

T. densleonis), the lettuce (Lactuca), the hawkweed (Hieraceum), and

others.

The ragweed family (Ambrosiaceæ) includes the ragweeds (Ambrosia), the

cockle-bur (Xanthium), and others.

The thistle family (Compositæ) includes the thistle (Carduus), asters

(Aster), goldenrods (Solidago), sunflowers (Helianthus), eupatoriums or

joepye-weeds, thoroughworts (Eupatorium), cone-flowers or black-eyed

Susans (Rudbeckia), tickseed (Coreopsis), bur-marigold or beggar-ticks

or devil’s-bootjack (Bidens), chrysanthemums, etc.

INDEX.

Absorption, 13, 22-28

Aceraceæ, 497

Acorn, 451

Acorus, 493

Æcidiomycetes, 218

Æcidiospore, 189

Æsculus hippocastanum, 498

Agaricaceæ, 199, 219

Agaricus arvensis, 206

Agaricus campestris, 200-207

Akene, 451

Albumen, 98

Albuminous, 98, 108

Alder, 495

Algæ, 136-176

Algæ, absorption by, 22

Alismaceæ, 493

Alpine formation, 474

Alpine plant societies, 483

Amanita phalloides, 207, 208

Amaranth, 495

Amaryllidaceæ, 494

Aments, 429

American mistletoe, 495

Ampelopsis, 498

Ancylistales, 215

Andreales, 249

Andrœcium, 319, 419

Anemophilous, 435

Angiosperms, morphology of, 318-348;

classification, 487

Antheridiophore, 227

Antheridium, 144, 149, 155, 176, 223, 228,

240, 245, 246, 266, 287, 433

Anthesis, 429

Anthoceros, 240, 241

Anthocerotales, 242

Anthocerotes, 242

Apogamy, 346

Apogeotropic (ap″o-ge″o-trop´ic), 126

Apogeotropism (ap″o-ge-ot′ro-pism), 126

Apple, 456, 497

Apple family, 497

Aquatic formations, 475

Aquatic plant societies, 486

Araceæ, 493

Archegonia (ar-che-go′ni-a), 223, 229, 233, 241, 244-246,

267, 288, 291, 307, 308

Archegoniophore, 229

Archegonium, 433

Archesporium (ar″che-spo´ri-um), 235

Archidiales, 249

Arctic formation, 481

Aril, 457

Arisæma, 493

Arisæma triphyllum, 442, 443

Aristolochiales, 495

Arrow leaf, 492

Arum family, 493

Asclepias, 500

Asclepias cornuti, 462

Ascomycetes (as-co-my-ce′tes), 195-198, 216-218

Ascus, 190, 213

Ash of plants, 79, 80

Ash tree, 500

Aspidium acrostichoides, 253, 257

Assimilation, 67, 109

Aster, 502

Atriplex, 495

Auriculariales, 218

Autotrophic plants, 85

Azalea, 499

Azolla, 296

Bacteria, 164, 165

Bacteria, nitrite and nitrate, 83

Bacteriales, 164, 165

Bacteroid, 93

Bangiales, 175

Basidiomycetes (ba-sid″i-o-my-ce′tes), 199-208, 218

Basidium, 201, 213

Bast, 50-52

Batrachospermum, 171-173, 175

Bazzania, 25

Beard-grasses, 480

Bedstraws, 501

Beechnut, 452

Beet, osmose in, 15, 16, 17, 18

Begonia, 407

Bellflower, 501

Berry, 454, 455, 456

Betulaceæ, 495

Bicuculla, 496

Bidens, 458

Bignonia, 501

Bilberries, 500

Biotic factors, 466

Birch, 495

Bird’s-nest fungi, 220

Blackberry, 454

Black fungi, 198

Bladderwort, 501

Blasia, 164, 236

Bloodroot, 496

Bluets, 436, 437, 501

Boletus, 209

Boletus edulis, 209

Boraginaceæ, 500

Botrychium, 295

Botrydiaceæ, 162

Botrydium granulatum, 146, 162

Broom-sedge, 480

Brown algæ, 167-170

Bryales, 349

Buckeye family, 498

Buckthorn, 498

Buckwheat, 495

Buds, winter condition of, 374-377

Buffalo-grass, 480

Bug seed, 495

Bulb, 372

Bunch-grasses, 480

Butternut, 452, 494

Buttonbush, 501

Buttonwood, 497

Cacti, 395, 498

Callithamnion, 173

Calyptrogen, 361

Cambium, 50, 52, 358, 363

Campanula rotundifolia, 442, 444, 510

Campanulales, 501

Canna, 445-449, 494

Capsella bursa-pastoris, 496

Capsule, 453

Carbohydrate, 71, 75, 80, 90

Carbon dioxide, 62-67, 110-113

Cardinal-flower, 501

Carpogonium, 172, 176

Carrot family, 499

Caryophyllaceæ, 496

Caryopsis, 451

Cassia marilandica, 402

Cassiope, 395

Castalia odorata, 496

Castor-oil plant, 497

Catalpa, 501

Catkin, 428

Cattail-flag, 492

Caulidium, 371

Cedar apples, 194

Cell, 3;

artificial 20

Cell-sap, 3, 40

Ceratopteris thalictroides, 296

Chætophora, 151, 162

Chætophoraceæ, 162

Chara, 176

Charales, 176

Chemical condition of soil, 466

Chemosynthetic assimilation, 109

Chenopodiales, 495

Chenopods, 495

Chestnut, 452, 494

Chicory family, 502

Chlamydomonas, 159, 160

Chlamydospores, 180

Chloral hydrate, 65, 87

Chlorophyceæ, 158

Chlorophyll, 2, 67, 72

Chloroplast, 68, 69, 71

Christmas fern, 251-253

Chromoplast, 71

Chromosomes, 342-345

Chroococcaceæe, 163

Chrysanthemum, 502

Chytridiales, 215

Cichoriaceæ, 502

Cichorium intybus, 502

Clavaria botrytes, 212

Clavariaceæ, 210, 219

Claytonia virginica, 496

Cleistogamous, 435

Clematis virginiana, 462, 463, 496

Climatic factors, 466

Climatic formations, 470

Clostridium pasteurianum, 93

Clover, 497

Club mosses, 284, 289

Coccogonales, 163

Cocklebur, 502

Cold wastes, 474

Coleochætaceæ, 162

Coleochæte, 153-156, 226

Collenchyma, 356, 363

Comandra, 495

Compass plants, 409

Compositæ, 502

Comptonia asplenifolia, 494

Cone-fruit, 456

Confervoideæ, 162

Coniferæ, 316

Conjugation, 137, 141, 160, 162, 179

Convallariaceæ, 494

Cooperia, 494

Cordyceps, 218

Coreopsis, 502

Cork, 357, 363

Corm, 373

Cortex, 50

Corymb, 427

Cotyledon, 99-101

Cranberry, 500

Cratægus, 497

Crowfoot family, 496

Cruciferæ, 496

Cryptonemiales, 175

Cucurbitaceæ, 501

Culture formations, 470, 475

Cultures, water, 28, 29

Cup fungi, 199

Cupuliferæ, 495

Cuscuta, 83, 500

Cushion type of vegetation, 483

Cuticle, 43

Cyanophyceæ, 163

Cyatheaceæ, 295

Cycadales, 316

Cycas, 311, 312, 457

Cyclosis, 9, 10

Cyclosporales, 171

Cyme, 430, 432

Cyperaceæ, 493

Cypripedium, 443, 447, 494

Cystocarp, 174

Cystopteris bulbifera, 260

Cystopus, 215

Cytase, 92, 108

Cytisus, 445

Cytoplasm (cy′to-plasm), 5

Dacryomycetales, 219

Dahlia, 108

Dandelion, 502

Dasiphora fruticosa, 497

Daucus carota, 499

Dehiscence, 453

Dentaria, 322-324

Dentaria diphylla, 496

Dermatogen, 359

Desert formation, 473

Desert societies, 480

Desmodium, 458

Desmodium gyrans, 399

Diadelphous (di″a-del′phous), 425

Diageotropism (di″a-ge-ot′ro-pism), 126

Diaheliotropic (di″a-he″li-o-trop′ic), 127

Diaheliotropism (di″a-he″li-ot′ro-pism), 127

Diastase, 77, 78, 108, 116

Diatoms, 166

Dichogamous (di-chog′a-mous), 437, 442

Dicentra, 496

Dicotyledons, 494

Dictyophora, 219

Diffusion, 13-20

Digestion, 107, 108, 109

Dimorphism of ferns, 273-280

Diœcious, 435

Dionæa muscipula, 133

Dipodascus, 216

Dipsacus, 501

Discomycetes, 217

Dodder, 83, 84, 500

Dogwood, 499

Dothidiales, 218

Downy mildews, 185

Drosera rotundifolia, 133, 496

Drupaceæ, 497

Drupe, 454

Duckweeds, 26, 28

Dudresnaya, 175

Dunes, 484

Ebenales, 500

Ecological factors, 464

Ecology (sometimes written œcology), 464

Ectocarpus, 167

Edaphic formations, 475

Elaphomyces, 217, 218

Elder, 501

Elm family, 495

Elodea, 61-63

Embryo of ferns, 269-272

Embryo sac, 326-328

Empusa, 215

Endocarp, 450

Endomyces, 216

Endosperm, 103, 105, 107, 306, 309;

nucleus, 327, 329-334

Entomophthorales, 215

Enzyme, 92, 98, 116, 117

Epidermal system, 358

Epidermis, 358, 359, 363

Epigæa repens, 499

Epigynous, 425

Epilobium, 498

Epinastic (ep-i-nas′tic), 129

Epinasty (ep′i-nas-ty), 129

Epipactis, 444, 447

Epiphegus, 84

Epiphytes, 416

Equisetales, 296

Equisetineæ, 296

Equisetum, 280-283

Ericaceæ, 499

Ericales, 499

Erythronium, 493

Etiolated plants (e′ti-o-la″ted), 68

Euascomycetes, 217

Eubasidiomycetes, 219

Eupatorium, 403, 502

Euphorbiaceæ, 497

Eurotium oryzæ, 78

Evening primrose family, 498

Exalbuminous, 108

Exoascus, 217

Exobasidiales, 219

Exocarp, 450

Fagales, 494

Fehling’s solution, 75, 76

Ferment, 98, 108, 116

Ferns, 251-279, 292, 457;

classification of, 295

Fertilization, 307, 308, 328, 329, 140, 145,

169, 172, 174, 197, 421

Fibrovascular bundles, 49-54

Figwort family, 501

Filicales, 295

Filicineæ, 295

Fittonia, 404

Flagellates, 83, 165

Flax, 497

Flower cluster, 419

Flower, form of, 422;

parts of, 419;

union of parts, 424

Flowers, arrangements of, 426;

kinds of, 421

Follicle, 453

Forest, formations 471;

societies, 477

Forests, relation to rainfall, 479

Fresh-water societies, 486

Frond, 352

Fruit, 450-457;

parts of, 450

Frullania, 25, 236

Fucus, 168-170

Fungi, absorption by, 22;

classification of, 213-222;

nutrition of, 86-90;

respiration in, 115

Gametangium (gam″et-an′gi-um), 140

Gamete (gam′ete), 138, 139

Gametophore (gam′et-o-phore), 230, 248

Gametophyte (gam′et-o-phyte), 225, 226, 244, 245, 250, 262, 270,

283, 292, 294, 305, 314, 317,

336-339, 340-348, 434

Gamopetalous (gam″o-pet′a-lous), 424

Gamosepalous (gam-o-sep′a-lous), 424

Gas in plants, 60-64

Gasteromycetes, 219

Gemmæ, 179, 235

General formations, 470

Gentian, 500

Geotropism (ge-ot′ro-pism), 125-127, 410

Geraniaceæ, 497

Geraniales, 497

Geranium family, 497

Germ, 459

Gigartinales, 175

Gingko, 313-315, 457

Gingkoales, 316

Ginseng, 499

Glasswort, 495

Gleicheniaceæ, 295

Glucose, 108. See sugar.

Gnetales, 316

Gonidia, 118, 143, 172, 174, 178-184

Gonidiangium (go″nid-an′gi-um), 178

Gonidium, 213

Gooseberry, 496

Goosefoot family, 495

Gracilaria, 173, 174, 175

Graminales, 492

Gramineæ, 492

Grape, 498

Grass family, 492

Grassland formation, 471

Green algæ, 158

Growth, 118-124, 380

Gulfweed, 170

Gymnosperms, 311, 456

Gymnosporangium, 194

Gynœcium, 320, 419, 451, 452

Gyrocephalus, 219

Halophytes, 468

Harpochytrium, 214, 215

Haustorium, 87, 88

Hawkweed, 502

Hawthorn, 497

Hazelnut, 452, 495

Head, 428

Heart-leaf, 495

Heath family, 499

Heliotrope, 500

Heliotropism (he-li-ot′ro-pism), 127-131, 133, 397

Helvellales, 217

Hemiascomycetes, 216

Hemibasidiomycetes, 218

Hepaticæ, 242

Heterospory (het″er-os′po-ry), 434

Heterothallic, 180

Heterotrophic plants, 85

Hickory, 494

Hickory-nut, 452

Hilum, 101, 102

Hippocastanaceæ, 498

Holdfasts, 418

Hollyhock, 498

Homothallic, 180

Honeysuckle, 501

Hormogonales, 163

Horse-chestnut, 498

Horsetails, 280-283

Houstonia cœrulea, 437

Huckleberry, 499

Humus saprophytes, 85, 91

Hybridization, 338

Hydnaceæ, 210, 219

Hydnum coralloides, 210

Hydnum repandum, 211

Hydrocarbon, 75

Hydrodictyaceæ, 161

Hydrophytes, 468

Hydropterales, 295

Hydrotropism (hy-drot′ro′pism), 133, 134, 412

Hygrophytes, 468

Hymeniales, 219

Hymenogastrales, 219

Hymenomycetes, 219

Hymenomycetineæ, 219

Hymenophyllaceæ, 295

Hypericum, 498

Hypocotyl (hy′po-co″tyl), 101

Hypocreales, 217

Hypogenous, 425

Hyponastic (hy-po-nas′tic), 129

Hyponasty (hy′po-nas-ty), 129

Hysteriales, 217

Impatiens, 498

Impatiens fulva, 460

Indian-pipe, 499

Indian turnip, 493

Indusium, 252

Inflorescence, 426

Insectivorous plants, 133, 496

Integument, 304

Intramolecular respiration, 113, 114

Inulase, 108

Inulin, 108, 417

Iodine, 65

Ipomœa, 500

Iridaceæ, 493

Iris, 493

Irritability, 125-135

Isoetales, 296

Isoetes, 289-291, 292

Isoetineæ, 296

Ivy, 498

Jack-in-the-pulpit, 373

Jewelweed, 498

Juglandales, 494

June-berry, 497

Jungermanniales, 242

Kalmia latifolia, 444

Karyokinesis, 341-344

Kelps, 168

Kingdom, 492

Labiatæ, 423, 501

Laboulbeniales, 218

Labrador tea, 499

Lactuca canadensis, 460

Lactuca scariola, 409, 460, 461

Lagenidium, 214, 215

Laminaria, 168, 169

Lamium, 424, 501

Larch, 367

Laurel, 499

Leaf patterns, 404

Leathesia difformis, 168

Leaves, form and arrangement, 383-391;

function of, 387;

protective modifications of, 392;

protective positions, 395;

reduction of surface, 394;

relation to light, 397;

structure of, 40-43, 131, 391, 393

Legumes, 92, 93, 453

Leguminosæ (= Papilionaceæ), 396, 399

Leitneria floridana, 494

Leitneriales, 494

Lemanea, 171, 173, 175, 492

Lemna, 418

Lemna trisulca, 26, 27

Lenticel, 357, 358

Lepiota naucina, 208

Lettuce, 502

Leucoplast, 71

Lichens, 86, 93-95, 220, 221

Light, 465

Liliaceæ, 490, 493

Liliales, 490, 493

Lilium, 489-493

Linaria vulgaris, 501

Linden, 498

Linum vulgaris, 497

Lipase, 108

Liquidambar, 496

Liriodendron, 496

Live-forever, 394

Liverworts, 222-239;

absorption by, 23-25;

classification of, 242

Lobelia, 501

Lupinus perennis, 353

Lycoperdales, 220

Lycopodiaceæ, 296

Lycopodiales, 296

Lycopodiineæ, 296

Lycopodium, 284-286

Macrosporangium, 94, 302, 304, 311, 312, 321

Macrospore, 287, 290, 326-328, 434

Magnolia, 496

Mallow family, 498

Malvales, 498

Maple family, 497

Marchantia, 24, 226-236

Marchantiales, 242

Marine plant societies, 486

Marratiales, 295

Marsilia, 370

Marsiliaceæ, 296

Matoniaceæ, 295

Medicago denticulata, 92

Medulla, 50

Members of the flower, 335

Members of the plant, 349-353

Meristem, 359

Mesocarp, 450

Mesophytes, 467

Microsporangia, 294, 299

Microspore, 287, 290, 299, 312, 435

Microsporophylls, 299, 320, 420

Milkweed family, 500

Mimosa, 132, 396

Mimulus, 501

Mint family, 501

Mistletoe, 84, 495

Mitchella, 501

Mixotrophic plants, 85

Mnium, 243-246

Molds, nutrition of, 86-90

Molds, water, 181

Monadelphous, 424

Monoblepharidales, 215

Monoblepharis, 215

Monocotyledons, 490, 492

Monœcious, 435

Monotropa uniflora, 499

Morchella, 198, 199

Morel, 198, 199

Morning-glories, 500

Mosaics, 405

Mosses, 243-248, 457;

absorption by, 25;

classification of, 248

Mucor, 6, 7, 15, 118, 119, 177-180, 215

Mucorales, 215

Mulberry, 495

Mullein, 366, 394, 501

Mushrooms, 199-208

Mustard family, 496

Mutation, 338

Mutualism, 95

Mycelium, 6, 86-90

Mycetozoa, 213, 214

Mycorhiza, 86, 91, 92, 217

Myosotis, 500

Myrica cerifera, 494

Myrica gale, 494

Myricales, 494

Myriophyllum, 403

Myrtales, 498

Myxobacteriales, 165

Myxomycetes, 83, 213, 214

Naiadaceæ, 492

Naiadales, 492

Naias, 492

Nemalion, 171, 172, 175

Nemalionales, 175

Nettle, 495

Nicotiana, 501

Nidulariales, 220

Nitella, 8, 9, 176

Nitrobacter, 83

Nitrogen, 92, 93

Nitromonas, 83

Nostocaceæ, 164

Nucellus, 304

Nucleus, 3, 4;

morphology of, 340-345

Nuphar advena, 496

Nutation, 123, 124

Nymphæa odorata, 496

Oak, 495

Oak family, 495

Œdogoniaceæ, 162

Œdogonium, 147-151, 350

Œnothera biennis, 498

Œnothera gigas, 338

Œnothera lamarkiana, 338

Olpidium, 214, 215

Onagar biennis, 498

Onagraceæ, 498

Onoclea sensibilis, 254, 273-278

Oogonium, 144, 150, 155

Oomycetes, 214, 215

Ophioglossales, 295

Ophioglossum, 295

Opuntiales, 498

Orchidaceæ, 494

Orchidales, 494

Orchids, 442

Oscillatoriaceæ, 163

Osmosis, 13-20

Osmundaceæ, 295

Ostrich fern, 279

Ovule, 302, 321, 334, 421

Oxalis, 497

Oxycoccus, 500

Oxydendrum arboreum, 501

Oxygen, 63, 110-113

Palisade cells, 41, 43

Palmaceæ, 493

Palmales, 493

Palms, 408

Pandanales, 492

Pandanus, 492

Pandorina, 160, 350

Panicle, 427

Papaverales, 496

Papilionaceæ, 423, 497

Parasites, 83, 84, 86

Parasitic fungi, nutrition of, 86-90

Parenchyma, 50, 356, 363

Parietales, 498

Parkeriaceæ, 296

Parmelia, 96

Parthenogenesis, 184

Partridge-berry, 501

Pea, 497

Pea family, 497

Pear, 456

Pediastrum, 161

Pellia, 164

Pellonia, 405

Peltigera, 94, 95

Pepo, 456

Pericycle, 360

Peridineæ, 166

Perigynous, 425

Perisperm, 331, 332

Perisporiales, 217

Peronospora, 183, 215

Peronosporales, 215

Persimmon, 500

Pezizales, 217

Phacidiales, 217

Phæophyceæ, 167

Phæosporales, 171

Phallales, 219

Phloem, 50-52, 360, 361, 363

Phlox family, 500

Phoradendron flavescens, 495

Photosynthesis, 67, 68, 70, 117

Phycomycetes (Phy″co-my-ce′tes), 214, 215

Phyllidium, 371

Phylloclades, 373, 395

Phyllotaxy, 375, 384

Physical condition of soil, 465

Physical factors, 465

Phytolaccaceæ, 495

Phytomyxa leguminosarum, 92

Phytophthora, 182, 184, 215

Pickerel-weed, 493

Pilularia, 296

Pinales, 216

Pine, white, 297-310

Piperales, 494

Pitcher-plant, 496

Pith, 50

Plant food, sources of, 81

Plant formations, 496

Plant substance, analysis of, 79, 80

Plantaginales, 501

Plantago, 501

Plasmolysis (plas-mol′y-sis), 19

Plasmopara, 183, 215

Plectascales, 217

Plectobasidiales, 220

Pleurococcaceæ, 161

Pleurococcus, 161

Plum family, 497

Plumule, 99

Podostemon, 496

Poison-hemlock, 499

Poison-ivy, 497

Poison-oak, 497

Poisonous mushrooms, 207, 208

Poison-sumac, 497

Pokeweed, 495

Polemoneales, 500

Pollen grain, 299, 305

Pollination, 303, 304, 420, 430, 433-449

Pollinium, 420

Polygonales, 495

Polygonum, 495

Polypodiaceæ, 296

Polyporaceæ, 209, 219

Polyporus, 209, 210

Polyporus mollis, 92

Polyporus sulphureus, 209

Pomaceæ, 497

Pondweeds, 492

Poppy, 496

Porella, 237

Portulaca, 495

Potamogeton, 492

Potato, 501

Powdery mildews, 195-198, 217

Primrose, 498, 500

Primula, 438

Primulales, 500

Procarp, 172, 174, 175

Progeotropism (pro″ge-ot′ro-pism), 126

Promycelium (pro″my-ce′li-um), 192

Proterandrous, 441, 442

Proterandry, 444

Proterogenous, 441, 442

Proterogeny, 440

Prothallium, 265, 287, 288, 291, 292, 304, 305,

311, 325, 328, 335, 433, 434

Protoascales, 216

Protoascomycetes, 216

Protobasidiomycetes, 218

Protococcoideæ, 158, 162

Protodiscales, 217

Protomyces, 216

Protonema (pro″to-ne′ma), 248, 264

Protoplasm, 1-12, 42-43, 342;

movement of, 7-11

Psilotaceæ, 296

Pteridophytes, 295, 434

Pteris cretica, 346

Puccinia, 187

Puff-balls, 220

Pumpkin, 501

Purslane, 495

Pyrenoid, 2, 3

Pyrenomycetes, 217

Pyrola, 499

Pyxidium, 453

Quercus, 495

Quillworts, 289-291

Quince, 456

Raceme, 427

Radicle, 99

Ragweed, 502

Rainy-season flora, 481

Ranales, 496

Ranunculaceæ, 496

Raspberry, 454, 455

Red algæ, 171, 174;

uses of, 175

Reproduction, 137, 143, 149, 154, 155, 179, 185, 186

Respiration, 110-116, 117

Rhamnales, 498

Rhizoids, 24-26

Rhizome, 354

Rhizomorph (rhi′zo-morph), 89

Rhizophidium, 214, 215

Rhizopus, 177-180, 215

Rhododendron, 499

Rhodomeniales, 175

Rhodophyceæ, 171

Rhus radicans, 416, 497

Riccia, 23, 164, 222-226

Ricinus, 497

Riverweed, 496

Root, function of, 410-418

Root hairs, absorption by, 19, 30, 32

Root hairs, action on soil, 82

Root pressure, 33, 34, 45

Root, structure of, 30, 361, 362

Root-tubercles, 92

Roots, kinds of, 415

Rosaceæ, 497

Rosales, 496

Rose family, 497

Rosette, 405

Rosette plants, 483

Rubiales, 501

Rudbeckia, 502

Rusts, 187-194

Salicaceæ, 494

Salix, 494

Salsify, 502

Salviniaceæ, 296

Samara, 451

Sandalwood, 495

Sanguinaria, 496

Santalales, 495

Sap, rise of, 53, 54

Sapindales, 497

Saprolegnia, 181-184

Saprolegniales, 215

Saprophytes, 83-85

Sargassum, 170

Sarraceniales, 496

Sarsaparilla, 499

Saxifrage, 496

Schizæaceæ, 295

Schizocarp, 451

Schizomycetes, 164

Schizophyceæ, 163

Sclerenchyma, 356-357, 361, 363

Scouring rush, 282

Screw-pine, 409, 492

Scrophulariaceæ, 501

Sedge family, 492

Seed, dispersal of, 458-463

Seed plants, 338

Seed, structure of, 98, 102

Seedlings, 97-107

Seeds, 330-334

Selaginella, 286-288, 292

Selaginellaceæ, 296

Sensitive fern, 273

Sensitive plants, 132, 396, 399

Sexual organs, 144, 147

Shadbush, 497

Shepherd’s-purse, 496

Shoot, floral, 419, 432

Shoots, 353-355;

types of, 361-373;

winter condition of, 374-377

Sieve tissue, 358, 363

Sieve tubes, 52, 53

Silique, 453

Silk-cotton tree, 417

Silver bell, 500

Siphoneæ, 146, 162

Skunk’s cabbage, 439-442

Slime molds, 83

Smoke-tree, 497

Societies, 475

Solanum, 501

Solidago, 502

Sourwood, 499

Spadix, 428

Spartium, 446

Spathyema fœtida, 438, 493

Spermagonia, 190

Spermatophytes, 338

Sphacelaria, 168

Sphærella lacustris, 158, 159

Sphærella nivalis, 158, 350

Sphæriales, 218

Sphagnales, 248

Sphagnum, 164

Spiderwort, 11, 493

Spike, 428

Spirodela polyrhiza, 27

Spirogyra, 1-5, 13, 14, 60, 72, 136-140, 350

Sporangia, 178-182

Sporangium, 253-258, 281, 290

Spores, 225, 256-258, 263, 264, 281

Sporocarp, 173

Sporogonium (spo″ro-go′ni-um), 224, 231, 233, 234, 237, 238,

239, 241, 246, 247, 248

Sporophyll, 274, 281, 292

Sporophyte (spo′ro-phyte), 225, 226, 232, 234, 237-239, 241, 242,

250, 261, 268, 270, 283, 292, 294, 314,

315, 317, 336-339, 340-348 434

Spurge family, 497

Squash, 501

Staminodium, 446

Starch, formation of, 68, 70-74;

changed to sugar, 77, 78;

translocation of, 73;

digestion of, 75

Stems, types of, 365-373

Stems, woody, structure of, 381-382

Stoma (pl. stomata) (sto′ma-ta), 42-44, 46

Strawberry, 455, 497

Sugar, test for, 75, 76

Sumac, 497

Sundew, 133, 496

Sunflower, 399-401, 502

Sweet gum, 496

Symbiosis, 85, 86, 92-95

Synergids (syn´er-gids), 327, 330

Syngenœsious, 424

Synthetic assimilation, 67

Tape-grass, 493

Taraxacum densleonis, 502

Teasel, 501

Telegraph-plant, 399

Teleutospore, 188

Temperature, 134, 135, 465

Tetrasporaceæ, 161

Tetraspores, 173, 174

Thallophytes, 352

Thallus, 352

Thelephoraceæ, 219

Thistle family, 502

Thunderwood, 497

Thyrsus, 427

Tilia, 498

Tillandsia, 493

Tissue, tensions of, 57-59

Tissues, classification of, 363, 364;

kinds of, 356-359;

organization of, 356-362

Toad-flax, 501

Tomato, 501

Tradescantia, 493

Tragopogon, 502

Trailing arbutus, 499

Trametes pini, 90

Transpiration, 35-46

Tremellales, 218, 219

Triadelphous, 425

Trillium, 318-322, 494

Trumpet-creeper, 501

Tuberales, 217

Tubers, 373

Tundra, 481

Turgescence, 14, 15

Turgor, 20;

restoration of, 56, 57

Typha, 493

Ulmaceæ, 495

Ulmus americana, 495

Ulothrix, 162

Ulotrichaceæ, 162

Ulvaceæ, 162

Umbel, 428

Umbellales, 498

Uredinales, 218

Uredineæ, 187-194, 218

Uredospore, 189

Uromyces caryophyllinus, 87

Urticales, 495

Ustilaginales, 218

Ustilagineæ, 218

Utricularia, 501

Vaccinium, 499

Vacuoles, 7, 8

Valerianales, 501

Vallisneria spiralis, 493

Variation, 338

Vascular tissue, 358, 363

Vaucheria, 142-146

Vaucheriaceæ, 162

Vegetation types, 464

Venus fly-trap, 133

Verbascum, 501

Verbena, 501

Vessels, 52, 53

Vetch, 92, 497

Viburnum, 501

Vicia sativa, 459

Viola cucullata, 436

Violaceæ, 498

Virgin’s bower, 462, 463

Viscum album, 84

Vitaceæ, 498

Volvocaceæ, 158

Walnut, 452, 494

Water, 465;

flow of, in plants, 53, 54

Water-lilies, 496

Water-plantain, 493

White pine, 396

Wild carrot, 499

Willow family, 494

Wind, 471

Wintergreen, 499;

leaf of, 43

Witch-hazel, 496

Wolffia, 28

Woodland formation, 470

Xerophytes, 467

Xylem, 50, 52, 360, 361, 363

Xylogen, 92

Xyridales, 493

Yeast, 216;

fermentation of, 115, 116

Yucca, 480, 493

Zamia, 313, 316, 457

Zoogonidia, 143, 149, 178-184

Zoospore, 149, 154

Zygomycetes, 215

Zygospore, 2, 138-140, 157, 160, 179, 180

Zygote (zy′gote), 138, 179

TWO NOTABLE NATURE BOOKS.

FERNS

A Manual for the Northeastern States. By C. E. WATERS,

Ph.D. (Johns Hopkins). With Analytical Keys Based

on the Stalks. _With over 200 illustrations_ from

original drawings and photographs. 362 pp. Square

8vo. Boxed. $3.00 _net_. (By mail, $3.34.)

A popular, but thoroughly scientific book, including

all the ferns in the region covered by Britton’s

Manual. Much information is also given concerning

reproduction and classification, fern photography, etc.

PROF. L. M. UNDERWOOD, OF COLUMBIA:

“It is really more scientific than one would

expect from a work of a somewhat popular nature.

The photographs are very fine, very carefully

selected and will add much to the text. I do not

see how they could be much finer.”

THE PLANT WORLD:

“This book is likely to prove the leading popular

work on ferns. The majority of the illustrations

are from original photographs; in respect to this

feature, it can be confidently asserted that _no

finer examples of fern photography have ever been

produced_.... May be expected to prove of permanent

scientific value, as well as to satisfy a want

which existing treatises have but imperfectly

filled.”

MUSHROOMS

Edible, Poisonous Mushrooms, etc. By Prof. GEO. F. ATKINSON,

of Cornell.

With recipes for cooking by Mrs. S. T. RORER, and

the chemistry and toxicology of mushrooms, by J.

F. CLARK. With 230 illustrations from photographs,

including fifteen colored plates. 320pp. 8vo. $3.00

_net_ (by mail, $3.23).

Among the additions in this second edition are ten

new plates, chapters on the “Uses of Mushrooms,” and on

the “Cultivation of Mushrooms,” illustrated by several

flash-light photographs.

EDUCATIONAL REVIEW:

“It would be difficult to conceive of a more

attractive and useful book, nor one that is

destined to exert a greater influence in the study

of an important class of plants that have been

overlooked and avoided simply because of ignorance

of their qualities, and the want of a suitable

book of low price. In addition to its general

attractiveness and the beauty of its illustrations,

it is written in a style well calculated to win the

merest tyro or the most accomplished student of the

fungi.... These clear photographs and the plain

descriptions make the book especially valuable for

the amateur fungus hunter in picking out the edible

from the poisonous species of the most common

kinds.”

THE PLANT WORLD:

“This is, without doubt, the most important and

valuable work of its kind that has appeared in this

country in recent years.... No student, either

amateur or professional, can afford to be without

it.”

HENRY HOLT AND COMPANY,

NEW YORK. (xii, ’03). CHICAGO.

=BRITTON’S MANUAL OF THE FLORA OF THE

NORTHERN STATES AND CANADA.=

By Director N. L. BRITTON

of the New York Botanical Garden.

1080 pp. 8vo. $2.25, net.

A comprehensive manual of over a thousand pages, containing

about 4,500 descriptions, probably one-third more than any other.

It is designed to meet modern requirements and outline modern

conceptions of the science. It is based on _An Illustrated

Flora_, prepared by Prof. Britton in co-operation with Judge

Addison Brown. The text has been revised and brought up to

date, and much of novelty has been added. All illustrations are

omitted, but specific reference has been made to all of the 4,162

figures in the _Illustrated Flora_.

“It is the most complete and reliable work that ever appeared

in the form of a flora of this region, and for the first time we

have a manual in which the plant descriptions are drawn from the

plants themselves, and do not represent compiled descriptions

made by the early writers.”—Prof. D. M. Underwood of Columbia.

“This work will at once take its place as the standard manual

of the region that it covers. It is far superior to any other

work of its class ever published in America.”—Prof. Conway

MacMillan of University of Minnesota.

“This book must at once find its way into the schools and

colleges, to which it may be commended for the students in

systematic botany.”—Prof. Chas. E. Bessey in “Science.”

“It is nothing if it is not compact; it is nothing if it is

not up to date; it is nothing if it is not the work of a master.

What more can be said, save that the more it is used the greater

the appreciation by the plant-lovers in the region which it

covers.”—Prof. Byron D. Halsted of Rutgers College.

“The work is well done; and as it is the only volume which

gives in a way suitable for students the present state of

the science, it cannot fail to take its place as a standard

work.”—Prof. George Macloskie of Princeton.

“I regard the book as one that we cannot do without and one

that will henceforth take its place as a necessary means of

determination of the plant species within its range.”—Prof. V.

M. Spalding of University of Michigan.

“An exceedingly valuable contribution to our botanical

literature.... It is convenient to handle, and the low price will

help to give it a large circulation.”—Prof. T. J. Burrill of the

University of Illinois.

HENRY HOLT & CO.

=29 West 23d Street, New York=

=378 Wabash Avenue, Chicago=

VIII, ’05

CHAMPLIN’S YOUNG FOLKS’

Cyclopædia of Natural History

By J. D. CHAMPLIN and F. A. LUCAS

With over 800 illustrations. 725 pp. $2.50

A whole “nature library” about animals prepared by

experts. Scientific facts are presented in simple

language, and are enlivened by anecdotes, personal

experiences, and references to history, art, and

literature.

The illustrations are not only superior as animal

pictures, but are genuinely illustrative, since they

show the creature in its natural surroundings and

characteristic action.

Extinct animals are fully treated, because these

strange forms are fascinating to children, and

because they illustrate the derivation of such

familiar living animals as birds, horses, and dogs.

“A full menagerie of all sorts of animals, with a

multitude of pictures.... A wonderful exhibition,

and the story of each individual is interesting

and calculated to stimulate the youthful mind in

research.... Pictures carefully reproduced, so that

they represent the creatures in their real forms and

proportions.”—_Brooklyn Eagle._

CHAMPLIN’S YOUNG FOLKS’

Cyclopædia of Literature and Art

With 270 illustrations. 604 pp. 8vo. $2.50

Brief accounts of the great books, buildings,

statues, pictures, operas, symphonies, etc.

“Few poems, plays, novels, pictures, statues, or

fictitious characters that children—or most of

their parents—of our day are likely to inquire

about will be missed here.... Mr. Champlin’s

judgment seems unusually sound—will be welcome and

useful.”—_Nation._

“Every schoolboy should have it on his study

table.... The range of the volume is very wide, for

besides those items of classical knowledge which

constitute the average school encyclopædia, we have

brief descriptions given of modern books, poems,

inventions, pictures, and persons about which

the lad of the period should be acquainted....

The pictures in the volume are varied and truly

illustrative. Old pictures and sculpture are

presented in the usual line of drawings, but modern

scenes and buildings are pictured through excellent

half-tone reproductions of photographs.”—_N. Y.

Times Saturday Review._

Earlier Volumes of Champlin’s Young Folks’ Cyclopædia.

With numerous illustrations. 8vo. $2.50 each.

COMMON THINGS. PERSONS and PLACES.

GAMES and SPORTS.

⁂ _12-page circular, with sample pages of Champlin’s Young

Folks’ Cyclopædias and his other books, free._

HENRY HOLT & CO.

=29 West 23d Street, New York=

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VIII, ’06

AMERICAN SCIENCE SERIES

_All prices are_ NET _unless marked_

RETAIL. _Details of the books will be found in

Henry Holt & Co.’s Educational Catalogue, free on application._

=Physics.= By Prof. GEORGE F. BARKER,

University of Pennsylvania.

_Advanced Course._ 902 pp. 8vo. $3.50

=Chemistry.= By Prest. IRA REMSEN,

Johns Hopkins University.

Chemistry. _Advanced Course._ 850 pp. 8vo. 2.80

College Chemistry, xx + 669 pp. 8vo. 2.00

Chemistry. _Briefer Course._

(_New Edition_, 1901.) 435 pp. 12mo. 1.10

Chemistry. _Elementary Course._ 272 pp. 12mo. 80c.

Laboratory Manual (_to Elementary Course_).

196 pp. 12mo. 40c.

Chemical Experiments. By Prof. REMSEN

and Dr. W. W. RANDALL. (_For Briefer

Course._) _No_ blank pages for notes.

158 pp. 12mo. 50c.

=Astronomy.= By Prof. SIMON NEWCOMB

of Johns Hopkins and EDWARD S. HOLDEN,

late Director of the Lick Observatory, California.

_Advanced Course._ 512 pp. 8vo. 2.00

The same. _Briefer Course._ 352 pp. 12mo. 1.12

The same. _Elementary Course._

By E. S. HOLDEN, 446 pp. 12mo. 1.20

=Geology.= By Profs. THOMAS C. CHAMBERLIN

and ROLLIN D. SALISBURY,

Univ. of Chicago. Vol. I., 684 pp., $4.00.

Vol. II. [_In press._]

=General Biology.= By Prof. W. T. SEDGWICK,

Mass. Institute of Technology,

and Prof. E. B. WILSON, Columbia Univ.

_Revised and Enlarged._ 231pp. 8vo. 1.75

=Botany.= By Prof. C. E. BESSEY,

Univ. of Nebraska.

_Advanced Course._ 611 pp. 8vo. 2.20

The same. _Briefer Course._ 356 pp. 1.12

=Zoology.= By Prof. A. S. PACKARD, Jr.,

Brown University.

_Advanced Course._ 722 pp. 8vo. 2.40

The same. _Briefer Course._ 338 pp. 1.12

The same. _Elementary Course._ 290 pp. 12mo. 80c.

=The Human Body.= By H. NEWELL MARTIN,

sometime professor in the Johns Hopkins University.

_Advanced Course._ 685 pp. 8vo.

(Copies without chapter on Reproduction sent

when specially ordered.) 2.50

The same. _Briefer Course._ (_Entirely

new edition, revised by Prof. G. Wells Fitz

of Harvard._) 408 pp. 12mo. 1.20

The same. _Elementary Course._ 261 pp. 12mo. 75c.

The Human Body and the Effects of Narcotics.

261 pp. 12mo. 1.20

=Psychology.= By Prof. WILLIAM JAMES

of Harvard.

_Advanced Course._ 689 + 704 pp. 8vo. 2vols. 4.80

The same. _Briefer Course._ 478 pp. 12mo. 1.60

=Ethics.= By Profs. JOHN DEWEY and

JAMES H. TUFTS, Chicago University.

(_In preparation._)

=Political Economy.= By the late President

FRANCIS A. WALKER,

Mass. Institute of Technology.

_Advanced Course._ 537 pp. 8vo. 2.00

The same. _Briefer Course._ 415 pp. 12mo. 1.20

The same. _Elementary Course._ 423 pp. 12mo. 1.00

=Finance.= By Prof. HENRY CARTER ADAMS,

University of Michigan.

_Advanced Course._ 573 pp. 8vo. 3.50

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VIII, ’02

CHEMISTRY

Cairns’s Quantitative Chemical Analysis

Revised and enlarged by Dr. E. WALLER.

417 pp. 8vo. $2.00, _net_.

Cohen’s Physical Chemistry for Biologists

Translated by Dr. MARTIN FISCHER,

Chicago University. 343 pp. 12mo, $1.75, _net_.

Congdon’s Qualitative Analysis

By Prof. ERNEST A. CONGDON,

Drexel Institute. 64 pp. _Interleaved._

8vo. 60c., _net_.

Nicholson and Avery’s Exercises in Chemistry

With Outlines for the Study of Chemistry.

To accompany any elementary text.

By Prof. H. H. NICHOLSON,

University of Nebraska, and

Prof. SAMUEL AVERY,

University of Idaho. 413 pp. 12mo. 60c., _net_.

Noyes’s (A. A.) General Principles of

Physical Science

An Introduction to the Study of the

Principles of Chemistry.

By Prof. A. A. NOYES,

Mass. Institute of Technology. 160 pp. 8vo. $1.50, _net_.

Noyes’s (W. A.) Organic Chemistry

By Prof. WM. A. NOYES,

Rose Polytechnic Institute. 534 pp. 12mo. $1.50, _net_.

Qualitative Analysis (Elementary) x + 91 pp. 8vo. 80c., _net_.

Remsen’s Chemistries By Pres. IRA REMSEN,

Johns Hopkins. (_American Science Series._)

=Inorganic Chemistry= (_Advanced_).

XXII + 853 pp. 8vo. $2.80, _net_.

=College Chemistry= XX + 689 pp. 8vo. $2.00, _net_.

=Introduction to Chemistry= (_Briefer_).

XIX + 435 pp. 12mo. $1.12, _net_.

This book is used in hundreds of schools and

colleges in this country. It has passed through

several editions in England, and has been translated

into German (being the elementary text-book in the

University of Leipsic), French, and Italian.

=Remsen and Randall’s Experiments=

(_for the “Introduction”_). 50c., _net_.

=Elements of Chemistry= (_Elementary_).

X + 272 pp. 12mo. 80c., _net_.

=Laboratory Manual=

(_for the “Elements”_). 40c., _net_.

Torrey’s Elementary Chemistry

By JOSEPH TORREY, Jr.,

Harvard. 437 pp. 12mo. $1.25, _net_.

White’s Qualitative Analysis

By Prof. JOHN WHITE,

Univ. of Nebraska. 96 pp. 8vo. 80c., _net_.

Woodhull and Van Arsdale’s Chemical Experiments

By Prof. JOHN F. WOODHULL

and M. B. VAN ARSDALE,

Teachers’ College, New York City.

136 pp. 12mo. 60c., _net_.

Extremely simple experiments in

the chemistry of daily life.

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VIII, ’05

CHAMBERLIN & SALISBURY’S

GEOLOGY

By THOMAS C. CHAMBERLIN and ROLLIN D. SALISBURY,

Professors in the University of Chicago.

(_American Science Series._) 2 vols. 8vo.

_Vol. I. Geological Processes and their

Results._ XIX + 654 pp. $4.00.

_Vol. II. Earth History._ [_In preparation._]

This is a notable scientific work by two of the

highest authorities on the subject in the United

States, and yet written in a style so simple that

it can be clearly understood by the intelligent

reader who has had little previous training in

the subject.

=Chas. D. Walcott=, _Director of U. S.

Geological Survey_:—I am impressed with the

admirable plan of the work and with the thorough

manner in which geological principles and

processes and their results have been presented.

The text is written in an entertaining style

and is supplemented by admirable illustrations,

so that the student cannot fail to obtain a

clear idea of the nature and work of geological

agencies, of the present status of the science,

and of the spirit which actuates the working

geologist.

=Henry S. Williams=, _Professor in Yale

University_.—I believe it is the best treatise

on this part of the subject which we have seen in

America.

=R. S. Woodward=, _Professor in Columbia

University_:—It is admirable for its science,

admirable for its literary perfection, and

admirable for its unequalled illustrations.

=T. C. Hopkins=, _Professor in Syracuse

University_:—It gives us the most advanced

thought on all the great questions of dynamical

and structural geology to be found in geological

literature.

=H. Foster Bain=, _U. S. Geological

Survey_:—The book is pre-eminently a teaching

book and I have no doubt that it will at once

become the standard American text-book on geology.

=William N. Rice=, _Professor in Wesleyan

University_:—The book is full of new ideas. It

is one of the indispensable books for the library

of every working geologist and every one who

wishes to be an up-to-date teacher of geology.

=T. A. Jaggar, Jr.=, _Assistant Professor

in Harvard University_:—The book appears to

be an excellent statement of modern American

geology, with abundant new illustrative material,

based upon the most recent work of government and

other surveys. It is especially satisfactory to

have in hand a geological volume which does not

attempt to cover the whole field. Modern geology

is much too large a subject to be condensed into

a single volume.

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VIII, ’05

THE METRIC SYSTEM.

[Illustration: 10-centimeter rule. The upper edge is in millimeters,

the lower in centimeters and half centimeters.]

UNITS. THE MOST COMMONLY USED DIVISIONS AND MULTIPLES.

{ _Centimeter_ (cm), 1/100 meter; _Millimeter_ (mm),

{ 1/1000 meter; _Micron_ (μ), 1/1000 millimeter.

THE METER, for { The micron is the unit in micrometry.

LENGTH { _Kilometer_, 1000 meters; used in measuring roads and

{ other long distances.

{ _Milligram_ (mg), 1/1000 gram.

THE GRAM, for { _Kilogram_, 1000 grams, used for ordinary masses, like

WEIGHT { groceries, etc.

THE LITER, for { _Cubic Centimeter_ (cc), 1/1000 liter. This is more

CAPACITY { common than the correct form, Milliliter.

_Divisions_ of the _units_ are indicated by Latin prefixes: _deci_,

1/10; _centi_, 1/100; _milli_, 1/1000.

_Multiples_ are designated by Greek prefixes: _deka_, 10 times;

_hecto_, 100 times; _kilo_, 1000 times; _myria_, 10,000 times.

TABLE OF METRIC AND ENGLISH MEASURES.

METER = 100 centimeters, 1000 millimeters, 1,000,000 microns,

39.3704 inches.

Millimeter (mm) = 1000 microns, 1/10 millimeter, 1/1000 meter, 1/25

inch, approximately.

MICRON (μ) (unit of measure in micrometry) = 1/1000 mm,

1/1000000 meter (0.000039 inch), 1/25000 inch, approximately.

Inch (in.) = 25.399772 mm (25.4 mm, approx.).

LITER = 1000 milliliters or 1000 cubic centimeters, 1 quart

(approx.).

Cubic centimeter (cc or cctm) = 1/1000 liter.

Fluid ounce (8 fluidrachms) = 29.578 cc (30 cc, approx.).

GRAM = 15.432 grains.

Kilogram (kilo) = 2.204 avoirdupois pounds (2⅕ pounds, approx.).

Ounce Avoirdupois (437½ grains) = 28.349 grams } (30 grams,

Ounce Troy or Apothecaries’ (480 grains) = 31.103 grams } approx.).

TEMPERATURE.

To change Centigrade to Fahrenheit: (C. × ⁹/₅) + 32 = F.

For example, to find the equivalent of 10° Centigrade,

C. = 10°, (10° × ⁹/₅) + 32 = 50° F.

To change Fahrenheit to Centigrade: (F. - 32°) × ⁵/₉ = C.

For example, to reduce 50° Fahrenheit to Centigrade,

F. = 50°, and (50° - 32°) × ⁵/₉ = 10° C.;

or - 40° Fahrenheit to Centigrade,

F. = - 40°, (- 40° - 32°) = - 72°,

whence - 72° × ⁵/₉; = - 40° C.

—_From “The Microscope” (by S. H. Gage) by permission._

Elementary Botany · 第 27 / 27 章