JOHN.

No. III.

In moving along the borders of the stream, we may observe, where the

sand or mud is fine and settled, a sort of mark or cutting, as if an

edged instrument had been drawn along, so as to leave behind it a track

or groove. At one end of this line, by digging a little into the mud

with the hand, you will generally discover a shell of considerable size,

which is tenanted by a molluscous animal of singular construction. On

some occasions, when the mud is washed off from the shell, you will be

delighted to observe the beautifully regular dark lines with which its

greenish smooth surface is marked. Other species are found in the same

situations, which, externally, are rough and inelegant, but within are

ornamented to a most admirable degree, presenting a smooth surface of

the richest pink, crimson, or purple, to which we have nothing of equal

elegance to compare it. If the mere shells of these creatures be thus

splendid, what shall we say of their internal structure, which, when

examined by the microscope, offers a succession of wonders? The

beautiful apparatus for respiration, formed of a network regularly

arranged, of the most exquisitely delicate texture; the foot, or organ

by which the shell is moved forward through the mud or water, composed

of an expanded spongy extremity, capable of assuming various figures to

suit particular purposes, and governed by several strong muscles, that

move it in different directions; the ovaries, filled with myriads, not

of eggs, but of perfect shells, or complete little animals, which,

though not larger than the point of a fine needle, yet, when examined by

the microscope, exhibit all the peculiarities of conformation that

belong to the parent; the mouth, embraced by the nervous ganglion, which

may be considered as the animal's brain; the stomach, surrounded by the

various processes of the liver, and the strongly acting but transparent

heart, all excite admiration and gratify our curiosity. The puzzling

question often presents itself to the inquirer: Why so much

elaborateness of construction and such exquisite ornament as are common

to most of these creatures, should be bestowed? Destined to pass their

lives in and under the mud, possessed of no sense that we are acquainted

with, except that of touch, what purpose can ornament serve in them?

However much of vanity there may be in asking the question, there is no

answer to be offered. We cannot suppose that the individuals have any

power of admiring each other, and we know that the foot is the only part

they protrude from their shell, and that the inside of the shell is

covered by the membrane called the mantle. Similar remarks may be made

relative to conchology at large: the most exquisitely beautiful forms,

colours, and ornaments are lavished upon genera and species which exist

only at immense depths in the ocean, or buried in the mud; nor can any

one form a satisfactory idea of the object the great Author of nature

had in view, in thus profusely beautifying creatures occupying so low a

place in the scale of creation.

European naturalists have hitherto fallen into the strangest absurdities

concerning the motion of the bivalved shells, which five minutes'

observation of nature would have served them to correct. Thus, they

describe the upper part of the shell as the _lower_, and the _hind_ part

as the front, and speak of them as moving along on their rounded convex

surface, like a boat on its keel, instead of advancing with the edges or

open part of the shell towards the earth. All these mistakes have been

corrected, and the true mode of progression indicated from actual

observation, by our fellow-citizen, Isaac Lea, whose recently published

communications to the American Philosophical Society reflect the highest

credit upon their author, who is a naturalist in the best sense of the

term.

As I wandered slowly along the borders of the run, towards a little

wood, my attention was caught by a considerable collection of shells

lying near an old stump. Many of these appeared to have been recently

emptied of their contents, and others seemed to have long remained

exposed to the weather. On most of them, at the thinnest part of the

edge, a peculiar kind of fracture was obvious, and this seemed to be the

work of an animal. A closer examination of the locality showed the

footsteps of a quadruped, which I readily believed to be the muskrat,

more especially as, upon examining the adjacent banks, numerous traces

of burrows were discoverable. It is not a little singular that this

animal, unlike all others of the larger gnawers, as the beaver, etc.

appears to increase instead of diminishing with the increase of

population. Whether it is that the dams and other works thrown up by men

afford more favourable situations for their multiplication, or their

favourite food is found in greater abundance, they certainly are quite

as numerous now, if not more so, than when the country was first

discovered, and are to be found at this time almost within the limits of

the city. By the construction of their teeth, as well as all the parts

of the body, they are closely allied to the rat kind; though in size,

and some peculiarities of habit, they more closely approximate the

beaver. They resemble the rat, especially, in not being exclusively

herbivorous, as is shown by their feeding on the uniones or muscles

above mentioned. To obtain this food requires no small exertion of their

strength; and they accomplish it by introducing the claws of their

fore-paws between the two edges of the shell, and tearing it open by

main force. Whoever has tried to force open one of these shells,

containing a living animal, may form an idea of the effort made by the

muskrat: the strength of a strong man would be requisite to produce the

same result in the same way.

The burrows of muskrats are very extensive, and consequently injurious

to dykes and dams, meadow banks, etc. The entrance is always under

water, and thence sloping upwards above the level of the water, so that

the muskrat has to dive in going in and out. These creatures are

excellent divers and swimmers, and, being nocturnal, are rarely seen

unless by those who watch for them at night. Sometimes we alarm one near

the mouth of the den, and he darts away across the water, near the

bottom, marking his course by a turbid streak in the stream:

occasionally we are made aware of the passage of one to some distance

down the current, in the same way; but in both cases the action is so

rapidly performed, that we should scarcely imagine what was the cause,

if not previously informed. Except by burrowing into and spoiling the

banks, they are not productive of much evil, their food consisting

principally of the roots of aquatic plants, in addition to the

shell-fish. The musky odour which gives rise to their common name is

caused by glandular organs placed near the tail, filled with a viscid

and powerfully musky fluid, whose uses we know but little of, though it

is thought to be intended as a guide by which these creatures may

discover each other. This inference is strengthened by finding some such

contrivance in different races of animals, in various modifications. A

great number carry it in pouches similar to those just mentioned. Some,

as the musk animal, have the pouch under the belly; the shrew has the

glands on the side; the camel on the back of the neck; the crocodile

under the throat, etc. At least no other use has ever been assigned for

this apparatus, and in all creatures possessing it the arrangement seems

to be adapted peculiarly to the habits of the animals. The crocodile,

for instance, generally approaches the shore in such a manner as to

apply the neck and throat to the soil, while the hinder part of the body

is under water. The glands under the throat leave the traces of his

presence, therefore, with ease, as they come into contact with the

shore. The glandular apparatus on the back of the neck of the male

camel, seems to have reference to the general elevation of the olfactory

organs of the female; and the dorsal gland of the peccary, no doubt, has

some similar relation to the peculiarities of the race.

The value of the fur of the muskrat causes many of them to be destroyed,

which is easily enough effected by means of a trap. This is a simple

box, formed of rough boards nailed together, about three feet long,

having an iron door, made of pointed bars, opening _inwards_, at both

ends of the box. This trap is placed with the end opposite to the

entrance of a burrow observed during the day-time. In the night, when

the muskrat sallies forth, he enters the box, instead of passing into

the open air, and is drowned, as the box is quite filled with water. If

the traps be visited and emptied during the night, two may be caught in

each trap, as muskrats from other burrows may come to visit those where

the traps are placed, and thus one be taken going in as well as one

coming out. These animals are frequently very fat, and their flesh has a

very wholesome appearance, and would probably prove good food. The musky

odour, however, prejudices strongly against its use; and it is probable

that the flesh is rank, as the muscles it feeds on are nauseous and

bitter, and the roots which supply the rest of its food are generally

unpleasant and acrid. Still, we should not hesitate to partake of its

flesh, in case of necessity, especially if of a young animal, from which

the musk-bag had been removed immediately after it was killed.

In this vicinity the muskrat does not build himself a house for the

winter, as our fields and dykes are too often visited. But in other

parts of the country, where extensive marshes exist, and muskrats are

abundant, they build very snug and substantial houses, quite as

serviceable and ingenious as those of the beaver. They do not dam the

water as the beaver, nor cut branches of trees to serve for the walls of

their dwellings. They make it of mud and rushes, raising a cone two or

three feet high, having the entrance on the south side, under water.

About the year 1804, I saw several of them in Worrell's marsh, near

Chestertown, Maryland, which were pointed out to me by an old black man

who made his living principally by trapping these animals for the sake

of their skins. A few years since I visited the marshes near the mouth

of Magerthy river, in Maryland, where I was informed, by a resident,

that the muskrats still built regularly every winter. Perhaps these

quadrupeds are as numerous in the vicinity of Philadelphia as elsewhere,

as I have never examined a stream of fresh water, dyked meadow, or

mill-dam, hereabout, without seeing traces of vast numbers. Along all

the water-courses and meadows in Jersey, opposite Philadelphia, and in

the meadows of the Neck, below the Navy-Yard, there must be large

numbers of muskrats. Considering the value of the fur, and the ease and

trifling expense at which they might be caught, we have often felt

surprised that more of them are not taken, especially as we have so many

poor men complaining of wanting something to do. By thinning the number

of muskrats, a positive benefit would be conferred on the farmers and

furriers, to say nothing of the profits to the individual.