CONTROVERSY ON THE LAYING OF EGGS
Home (1802), the first anatomist to examine the platypus, suggested
that, from the nature of the reproductive organs in the female, it
might be ovi-viviparous. In 1819 (p. 238) he makes a categorical
statement, without giving any evidence in support, as follows:--
“In the ornithorhynchi the yelk-bags are formed in the ovaria;
received into the oviducts, in which they acquire the albumen, and
are impregnated afterwards; the foetus is aerated by the vagina, and
hatched in the oviduct, after which the young provides for itself,
the mother not giving suck.”
Had this been put forward as merely the probable course of events,
there would perhaps have been some justification for it. But it is
given as a statement of fact, and it is hard to imagine how a worker
of Home’s standing could have committed himself to so dogmatic a
statement--which time has proved to be entirely erroneous, and for
which not one jot of actual evidence existed at the time it was written.
Blumenbach (1801), after a study of the skull, suggested that the
platypus might be oviparous; but although this long shot ultimately
received confirmation, it hardly seems necessary to credit the
Göttingen anatomist with any very remarkable acumen.
Those zoologists who considered the platypus to be definitely a mammal,
of course believed that it brought forth its young alive. Among these
we may include Blainville, Cuvier, and Oken. The last-named suggested
(1817) that the mammary glands might occupy some unusual situation,
and so might have escaped notice; later (1823), commenting on the
ovarian ovum described by Dr. Patrick Hill (see below), he points out
its resemblance to the mammalian Graafian follicle, and concludes by
saying that the tales of oviparity and ovi-viviparity have all arisen
from failure to observe the mammary glands. Oken’s assurance of the
existence of mammary glands was justified, as we have seen, by the
discovery of these glands by Meckel, announced in 1824.
[Illustration: VENTRAL VIEW OF MALE PLATYPUS.
The spurs are concealed behind the heels. In this specimen the hair is
almost entirely worn off the under surface of the tail.
_Plate 7_]
It seemed likely, then, that despite the opposition of Etienne Geoffroy
and the extraordinary form of the animal itself and of its reproductive
apparatus, _Ornithorhynchus_ would turn out to be quite an ordinary
mammal, which produced its young alive. But persistent statements came
from the colonists of New South Wales that it laid eggs. Sir John
Jamison (1818, p. 585) wrote, without comment, and as if citing an
established fact:--“The female is oviparous, and lives in burrows in
the ground.” This would seem to indicate that nesting-burrows and eggs
had been definitely observed. But no actual evidence was forthcoming to
calm the agitation of European zoologists.
Dr. Patrick Hill (1822, p. 623) examined what he believed to be an
impregnated female, in the left ovary of which was a large Graafian
follicle. This specimen was taken to England by a Mr. Scott, and, as
is recorded in a footnote, was presented to the University of Oxford.
Hill’s error as to the nature of the ovum gave rise to a considerable
misunderstanding. Fleming (1822, p. 215) stated that the eggs of
_Ornithorhynchus_ had been transmitted to London; although he was aware
that these ‘eggs’ were merely ovarian ova, this statement was repeated
in several French works. Hill concluded his letter with the following
words:--“Cookoogong a native, chief of the Boorah-Boorah tribe, says,
that it is a fact well known to them, that this animal lays two eggs,
about the size, shape, and colour of those of a hen; ...” As the egg
of the platypus measures only three-quarters of an inch in length,
Cookoogong’s estimate of the size is rather wide of the mark; but this
may have been due to misunderstanding on the part of Hill.
In 1824 an anonymous article, “Quelques observations nouvelles sur
l’Ornithorhynque,” appeared in the _Annales des Sciences Naturelles_,
(Vol. II). Quite possibly it was written by Geoffroy St.-Hilaire. On
p. 75 the following words appear:--“On a vu à la Nouvelle-Hollande
des oeufs d’Ornithorhynque, et c’est M. Jameson, l’un des principaux
propriétaires et habitans de Botany-Bay, qui guarantit ce
renseignement.” Jamison’s statement that the platypus lays eggs has
here been converted into a definite assertion that the eggs have been
seen.
In Vol. X of the same journal (1827) a second unsigned article
appears:--“Sur les Habitudes de l’Ornithorhynque”--the account
of the habits being quoted from the _Antologia di Firenze_,
XXIV, p. 305, where also it appears anonymously. On p. 193 we
read--“_Ornithorhynchus_ inhabits the marshes of New Holland. It makes
among tufts of reeds bordering the water a nest composed of down
and interlaced roots, in which it deposits two white eggs, smaller
than those of ordinary fowls: it broods on them for a long time,
hatches them like a bird, and only abandons them when threatened by a
formidable enemy.” The author of the article comments (pp. 194-5):--“We
regret that the _Antologia_ usually omits to make known the source
whence it borrows the curious facts which it communicates to its
readers. What we have just read bears a tolerably faithful resemblance
to an account by Patrick Hill, ... but it differs in being more
precise; which leads us to believe that it may be borrowed from another
and a newer source.” It is quite obvious that the account was drawn
from Hill, the greater precision being due to the journalistic sense of
the writer.
However, these statements about eggs stirred Etienne Geoffroy to
make enquiries, and the article closes with a quotation from a
letter written by Southwood Smith to Milne Edwards in reply to
Geoffroy:--“There are no eggs of _Ornithorhynchus_ with the Linnean
Society, nor in any other collection in London. One preparation had
been seen, and was said to be furnished with an egg; Sir Everard Home
had examined it, and was convinced that this was a mistake. This man
of science added that no one had taken more trouble than himself to
resolve all doubts on the subject of _Ornithorhynchus_, and that he had
hopes of doing so, having interested the Secretary of State for the
Colonies in this research.” This is a fairly literal translation of
the French, as it appears in the _Annales_. The letter may have been
written in English, in which case the re-translation of a translation
would be certain to differ considerably from the original.
Lesson, writing in the _Annales_, Vol. VI (1825), says on p. 249:--
“Mr. Murdoch, superintendent of the farm at Emu Plains, assured me
that he had found the eggs of _Ornithorhynchus_, and that they are of
the size of those of a domestic fowl.”
In Vol. XVIII (1829) Etienne Geoffroy, flushed with triumph, produced a
description and figure of veritable eggs. He writes on pp. 160-164:--
“But this fact, the more decisive as it is a fortunate confirmation
of old stories, has just been sent to me by the learned Professor of
Comparative Anatomy and Zoology in the free university lately founded
in London, Mr. Robert E. Grant: this is, that _Ornithorhynchus_
certainly lays eggs. I publish the full text of the letter which this
savant has sent me; it is written from London, from the headquarters
of the new university, under the date 14th September, 1829.
“Mr. Grant’s Letter.
“Sir,--
“My return to London has been delayed, as I stopped at Calais,
Boulogne, Dover, and other places in England for the purpose of
making zoological investigations on the coasts; but having now
arrived here, I experience very great pleasure in communicating to
you the information which I have just received, and which I have
obtained from Mr. Leadbeater, concerning the eggs which he possesses,
and which are said to be those of _Ornithorhynchus_.
“Mr. Holmes, well known to most naturalists in London as a gatherer
of natural history collections, has lived for some years in New
Holland. One day while hunting on the banks of the Hawkesbury, a
river in the interior of the country, he saw very distinctly, some
feet away, an _Ornithorhynchus_ leave a sandbank and escape in the
river. On examining the place where the animal had rested, Mr. Holmes
saw a hollow in the sand about nine inches in diameter, and in this
open cavity were some small twigs and the eggs in question.
“He found there four eggs:--all were brought to England, together
with a collection of birds of the country. Mr. Holmes has since
returned to New Holland, with his wife and family. Two of these
eggs are in the Manchester Museum; the other two were given to Mr.
Leadbeater, who will not part with them, neither for cash nor for any
other consideration: he has refused to sell them to Sir Everard Home,
to various other naturalists, and to myself.
“At the same time, despite the remarkable agreement of these facts
with the results of your profound studies, you will only accord to
this evidence such confidence as is due.
“These eggs seem to me to differ, in form and texture, from those of
birds; they are remarkable for their regular spheroidal-oblong shape,
of an equal width at both ends; they measure 1⅜ inches in length, by
a breadth of ¾-inch; the shell is thin, fragile, semi-transparent,
and of a uniform flat white colour; its external surface, under a
lens, shows a wonderfully woven network; the calcareous matter forms
the white walls of its innumerable and very minute cavities, which do
not prevent the surface from remaining somewhat polished. One of the
eggs was broken, and I examined its inner surface, which seemed also
to be formed by the deposition of very small grains of calcareous
matter.
“The size and shape of these eggs recall the eggs of lizards and
snakes, reptiles which have not, however, a tenth of the bulk of an
_Ornithorhynchus_.
“My friend Mr. Yarrell, who has also examined the eggs, thinks that
they differ as much from those of birds as from those of reptiles.
Other travellers have told me that the Hawkesbury River, on the banks
of which these eggs were found, is reputed in that country to harbour
great numbers of _Ornithorhynchus_.
“Mr. Holmes has been back in New Holland for nearly a year: and he
will again be directing his attention to this matter.
“I regret being reduced to so few facts for communication to you on
this subject of so great interest to science.
“I place at the bottom of my letter a drawing, made with the greatest
care, of the entire egg which I saw at Mr. Leadbeater’s; it is shown
natural size, and with the precise detail of its shape.
“Robert E. Grant.”
But, alas for the hopes of M. Geoffroy, this drawing, which he
reproduces in Plate 3, is so faithfully done that an Australian
zoologist has no difficulty in recognizing it as the egg of the common
long-necked tortoise (_Chelodina longicollis_). Geoffroy was, of
course, unaware of this. When, however, he came to consider the size
of the egg, he realized that it could not possibly pass through the
pelvic ring of the female platypus, the diameter of which was but
five-twelfths of an inch, while that of the egg was nine-twelfths.
Nothing daunted, Geoffroy first supposed that the egg passed to the
cloaca in a not fully developed condition, and that it underwent
further development there, but so rapidly as not to cause serious
obstruction. Later, however, in 1833, he discarded this view, and
believed that it remained in the oviduct until hatching took place,
since it could not pass through the small pelvis. He would seem to have
conveniently forgotten that the eggs were found laid in a nest in the
sand.
Though, in support of oviparity, Geoffroy fell so often into error, he
ultimately proved right. The great Richard Owen, on the other hand,
through too firm and convinced a belief in ovi-viviparity, rejected
evidence which, in the light of our later knowledge, was convincing
enough; in the upshot he was proved wrong. The first piece of positive
evidence was given by Lieutenant the Hon. Lauderdale Maule, of the
39th regiment, in a letter to Dr. Weatherhead, extracts from which were
communicated to the Zoological Society of London and printed on pp.
145-6 of the volume for 1832. Maule writes:--
“During the spring of 1831, being detached in the interior of New
South Wales, I was at some pains to discover the truths of the
generally accepted belief, namely, that the female Platypus lays eggs
and suckles its young.”
He goes on to say that he found and opened up a number of
nesting-burrows, of which he gives a summary description. He obtained
young which were forwarded to Dr. Weatherhead, and described by Owen;
but “no eggs were found in a perfect state, but pieces of a substance
resembling egg-shell were picked out of the debris of the nest” (p.
155). There is no reason to doubt that these were actually egg-shells,
but Owen ignores this statement altogether, and Broderip (1840) writes
in the _Penny Cyclopaedia_:--“The supposed portions of egg-shell found
by Lieutenant Maule in the nest were probably portions of excrement,
coated, as in birds, with the salts of the urine, that secretion and
the faeces being expelled by the same orifice.”
It is probable that Owen based his views on the evidence of Dr. George
Bennett, who spent many years in endeavouring to penetrate the secrets
of the furtive and mysterious platypus. Bennett obtained impregnated
females, and forwarded uteri containing ova to Owen, who described them
in 1834. He also found young, but did not succeed in getting eggs, and
became convinced that the young were brought forth alive. He tried
to get precise information from the aborigines, but, again probably
through lack of understanding, failed. We read on pp. 122-3 of his
_Gatherings of a Naturalist_:--
“The various contradictory accounts that have been given, on the
authority of the aborigines (who might be supposed, from their so
often seeking these animals for food, to be able to state their
habits correctly), as to the animal laying eggs and hatching them,
induced me to take some pains to find out the cause of such an error,
and being now perfectly satisfied as to the contents of the uteri,
I could the more readily determine the accuracy or inaccuracy of
the accounts which I might receive from the natives. I determined,
however, not to ask any person who had been repeatedly questioned
before on the same subject; but some time after, when I visited the
out-stations in the Tumat country, where such questions had never
been previously asked, I made inquiries among the most intelligent.
The Yas natives at first asserted that the animals lay eggs, but
very shortly afterwards contradicted themselves. To ascertain what
dependence could be placed on them, I made a drawing of an oval egg,
which was recognized to be like that of the Mallangong. I then made
a drawing of a round egg, and that also was declared to be ‘cabango’
(egg) of the Mallangong. It was also declared that ‘old woman have
eggs there in so many days’ (the number of which they did not know),
that the young ones ‘tumble down,’ and that two eggs are laid in one
day. An account subsequently obtained from a native, who appeared
anxious to explain the fact, would lead to the belief that the
animal is ovi-viviparous; but yet, from the difficulty they find in
expressing themselves in our language, we often misunderstand them.
He asserted the animal to be oviparous; but when desired to procure
the egg, he replied, ‘Bel cabango (no egg) tumble down; pickaninny
tumble down.’
“In the Tumat country the answers were readily and satisfactorily
given; and afterwards, more minute questions being put to them
through my interpreter, the result was the same. ‘Tambreet no make
egg (corbuccor) tumble down; pickaninny make tumble down,’ was their
reply. This accorded with my observations; for it was at the season
when this inquiry was made that the young platypi were found in the
burrow, as if just brought forth.”
Had Dr. Bennett relied more on individual effort instead of on
aboriginal information, this vexed question could have been settled
there and then.
The next account is that given by M. Jules Verreaux, of the Paris
Museum, who spent some time in Tasmania; he wrote an article
“Observations sur l’_Ornithorhynque_” in the _Revue Zoologique_ for
1848. This article contains a curious admixture of fancy with some
of which we shall have to deal later. The only point that interests
us here is that on p. 130 Verreaux declares himself quite sure that
the animal is ovi-viviparous, without giving any justification for his
assertion. Owen (1848) reviews this article, and on p. 318 comments
on Verreaux’s statement, which, apparently, he is quite prepared to
accept, suggesting that it is based upon the same kind of evidence
that has led to his own conclusions. He deplores the lack of absolute
proof, but sets out in a footnote the reason for his belief: “It is to
the absence of this proof that Dr. Carpenter appears to refer, where
he remarks, in his excellent _Principles of Human Physiology_, 1842,
p. 40, ‘No _positive_ evidence has yet been obtained that its young
are born alive.’ The minute size of the ovarian ovum and consequently
of the vitellus; the presence of small ova with a delicate chorion and
without chalazae or shell, in the uterine portion of the oviduct; the
absence of any shell-forming portion of the oviduct--all are elements
of a body of _positive_ evidence in favour of the ovi-viviparity of the
_Ornithorhynchus_, which needs only the discovery of the foetus _in
utero_ for decisive confirmation.”
In 1865 (1865, pp. 683-4) Owen published, with comment, two interesting
letters from Australia, which are worth quoting in full:--
“Wood’s Point, September 21st, 1864.
“To Professor R. Owen.
“Sir,--I have great pleasure in being able to inform you of a
very interesting discovery in the economy of the _Ornithorhynchus
paradoxus_, and one which I have no doubt you will hail with delight.
About ten months ago, a female Platypus was captured in the River
Goulburn by some workman who gave it to the Gold-Receiver of this
district. He, to prevent its escape, tied a cord to its leg and put
it into a gin-case, where it remained during the night. The next
morning, when he came to look at it, he found that it had laid two
eggs. They were about the size of a crow’s egg, and were white, soft,
and compressible, being without shell or anything approaching to a
calcareous covering.
“I had an opportunity of examining them externally, and I found no
evidence of their having had any recent vascular connexion with the
maternal organs; but I am sorry to say that I never had a chance of
examining their contents, as, on inquiring for them a day or two
afterwards, I found they had been thrown away, much to my chagrin and
disappointment.
“The animal itself was afterwards killed (next day), and I was told
that numerous ova (in the words of my informant ‘eggs’) were found in
it, in various stages of development, which in the aggregate somewhat
resembled a bunch of grapes; but this I cannot personally vouch for.
“It may appear to you a matter of surprise that I did not examine
more minutely this interesting animal; but I am sorry to say that the
same spirit that dictated the throwing away of the eggs, prevented me
making a more detailed investigation.
“I am in hopes that I shall be able to get another pregnant specimen;
if so, I shall have much pleasure in sending it to you for your
inspection.
“I have the honour to be, Sir,
“Your obedient Servant,
“Jno. Nicholson, M.D., etc.”
“Wood’s Point, Victoria, Australia.”
By a later mail Owen received from Dr. Mueller a letter from the
“Gold-Receiver” referred to by Dr. Nicholson. It had been written in
reply to enquiries, which vague reports of the occurrence had induced
Dr. Mueller to make.
“Woods’ Point, September 25, 1864.
“Dear Sir,--In reply to your enquiries relative to the
_Ornithorhynchus paradoxus_, I must in the first place correct an
erroneous impression which the newspaper paragraph has conveyed.
“The Platypus is not now in my possession, and the eggs were laid the
day after its capture. The animal was captured in the Goulburn and
given to me. It was then fastened by a cord in a gin-case, and on
examining it the next morning the two eggs were found in the bottom
of the box, both of them having undoubtedly been laid during the
night. In the course of the day the creature was killed by a _would
be_ scientific friend of mine, with the intention of preserving its
skin; and on opening the body the ovaries were found to be clustered
with ova in different stages of growth; but none of them so large as
the eggs which were laid. These eggs were white, soft, and without
shell, easily compressible, and about the size of a crow’s egg.
“Not being sufficiently versed in the subject I am not prepared to
say whether these eggs might not have been abortions caused by fear,
but there was no appearance on the surface of their ever having been
vascularly connected with the maternal uterus, and reviewing all the
facts observed I should undoubtedly say that the animal was oviparous.
“I am, dear Sir,
“Yours faithfully,
(Signed) “Geo. J. Rumby.”
Owen comments as follows upon these letters:--
“Assuming the fact of the oviposition in the month of December 1863
(Dr. Nicholson writes of the occurrence as having happened ‘about
ten months’ before the date of his letter, September 21, 1864) by a
female _Ornithorhynchus_, of two ova, about the size of a crow’s egg,
‘white, soft, compressible, without shell or anything approaching to
a calcareous covering,’ the question is--What did they contain? Had
the unvascular chorion been cut or torn open, an embryo or a yelk
might have been seen. Better still would it have been if both ova had
been at once immersed in a bottle of whatever colourless alcoholic
liquor might be at hand. Probably no medical man had ever an
opportunity or a chance of settling a point in comparative physiology
of more interest, and with less trouble, than the gentleman who was
privileged to be the first person to see and handle the new-laid eggs
of the _Ornithorhynchus paradoxus_.”
I can sympathize with Owen in his disappointment. It would indeed be
interesting to know what was inside those eggs. Probably young birds!
However, without that knowledge it is not possible to decide whether
they were the first eggs known to have been laid by a platypus. If the
size mentioned by both Nicholson and Rumby is correct, they could not
have been the eggs of _Ornithorhynchus_, which have but a third of
the length and a tenth of the bulk of any Australian bird’s egg that
could justifiably be referred to as that of a crow. The words “soft”
and “compressible” in their descriptions are perplexing; if correct,
then the size was wrong, and, if incorrect, the probability is that a
practical joker introduced birds’ eggs.
At the outset Owen appears to have accepted this account at proving
that _Ornithorhynchus_ was oviparous; but later he inclined to the
belief that the eggs might have been “abortions due to fear,” and was
still enquiring for definite evidence.
In the _Australian Journal of Education_ (vol. ii, 1869) there is
a series of articles on the fauna of Australia, most of which are
unsigned. That on the platypus appears on pages 104-5, under the
pseudonym “Five Dock;” it contains nothing of any particular interest
except a statement that the egg-laying idea is “exploded.”
On p. 16 of the _Proceedings of the Royal Society of Tasmania_ (1878)
we read:--
“Some members having expressed their opinion that the question as to
the animal being oviparous had long been settled in the negative, Mr.
E. D. Swan remarked that Professor McCoy, who would be recognized by
all as an authority of the greatest weight, had recently written to
the effect that he had received evidence of a most reliable character
that the _Ornithorhynchus_ was oviparous.”
But I cannot find that McCoy ever published this evidence.
In the same journal for 1879 Dr. Crowther makes some interesting
observations on the platypus, and remarks on p. 96:--“when I tell you
that the foetus has been found in utero, and in a hairless condition
in the burrow ... (The former of these startling facts I hope to
demonstrate to this society soon.)” It is hardly necessary to point out
that this hope was never fulfilled.
The matter was not finally settled until 1884. In that year W. H.
Caldwell, a Cambridge zoologist who came to Australia specially to
investigate the reproduction of monotremes and marsupials, obtained
eggs of both platypus and echidna in the Burnett River district of
Queensland. He writes (1887, p. 464):--“In the second week of August I
had similar stages in _Ornithorhynchus_,[2] but it was not until the
third week that I got the laid eggs from the pouch of _Echidna_. In the
following week (August 24) I shot an _Ornithorhynchus_ whose first egg
had been laid; her second egg was in a partially dilated _os uteri_.
This egg, of similar appearance to, though slightly larger than, that
of _Echidna_, was at a stage equal to a 36-hour chick. On the 29th
I sent in the telegram ‘Monotremes oviparous, ovum meroblastic’ to
a neighbouring station, where it would meet the passing mail-man,
addressed to my friend Professor Liversidge, of the Sydney University,
asking him to forward it to the British Association at Montreal.”
Caldwell’s cable was read before the Montreal meeting of the British
Association for the Advancement of Science in September, 1884, and
the scientific world at last had the solution of a question which had
troubled it for more than eighty years. Monotremes laid eggs. By a
curious coincidence, W. Haacke found on 25 August, 1884, an egg-shell
in the pouch of an echidna, and exhibited it before the Royal Society
of South Australia on 2 September, the very day on which Caldwell’s
cable was read in Montreal. Haacke has made the claim that he first
discovered the oviparous nature of the monotremes, but there can be no
question that Caldwell has priority.