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Journal of Proceedings.
aquatic free larval stage being consequently altogether suppressed.* It
was well known that in certain species of Batrachia, as for instance the
Surinam Toad (Pipa Americana), the eggs are carried about by the female
until hatched into young toads; and the tadpole stage is passed within
the egg,. And an American species of Tree-frog (Hylodes) lays its eggs in
the axils of leaves, where only a few drops of water could at any time
collect.
The President said that he had listened to Mr. Wilson's observations
with very great interest. The phenomenon described he had long believed
to occur, but Mr. Wilson's was the first direct evidence on the point he
had met with. He entered into a full explanation of the bearing of the
instance observed upon the known facts with respect to the development
of some species of Urodela, in which the larval form is a perfect animal
(Axolotl) and one capable of reproduction, but which, under certain con-
ditions, becomes transformed into a creature formerly placed in quite
another genus (Amblystoma). It was very interesting to find in our native
species of Batrachia a tendency to retain permanently the larval form,
and he hoped Mr. Wilson would institute some experiments to discover, if
possible, the nature of the conditions leading to this abnormal retardation
of development. From Mr. Wilson's account he gathered that the tad-
poles could not land, and he would suggest that possibly free access to
land so as to be enabled to breathe air was necessary for the development
of the lungs, and consequently, by correlation of growth, for the appear-
ance of the perfect animal.
Mr. Wilson promised to make some experiments as suggested. His
own impression was that plentiful and suitable food was necessary for due
development. The water in the bell-glass had evaporated to about half;
it was clear and healthy, of a brown colour like a dark topaz ; the weeds
were bright green and in vigorous growth. But he fancied that the want
of plentiful and varied food had so far discontented the tadpoles that
they had neglected their proper functions and failed in their duty to
Nature! As an instance of the adaptability of Batrachians to varied
conditions, he might mention that in years gone by he had seen, in a dry
stone quarry, pale yellow slender newts shrivelled and dried up to an inch
and-a-half in length, bones and all, and yet alive ; the same newts that
in a wet season, when the stone quarry stood three feet in water, were of
a dark fine colour, and wriggled their graceful way through the rocky
pools, active and well, measuring seven or eight inches in length, †
* Since the above meeting Mr. Meldola has reminded me that in the European Land-
Salamanders (which are ovo-viviparous) the larvae, when born, have sometimes lost their
external branchiae, and that in Salamandra atra the entire branchiate stage is passed
within the body of the mother. As, however, these Urodela are normally ovo-viviparous,
while the Anoura are oviparous, the fact does not much aid my suggestion, and I am
bound to say that I am not able to point to any positive confirmatory observations. I
shall be very glad of information.—W.C.
† A valuable discussion of the whole subject will be found in Mr. Meldola's translation
of Dr. Weismann's ' Studies in the Theory of Descent,' London, Sampson Low,
Marston and Co., 1882. Vol. ii. pp. 555—633.—Ed.