Miscellaneous. 44.7 
a peculiar interest inasmuch as it confirms the justice of Cuvier’s 
supposition when he said, without having been able to obtain any 
direct proof of it, that the axolotl, although regarded as a Perenni- 
branchiate Batrachian, would prove to be a larva. 
I have not time to enter upon an examination of the different 
questions which arise from these unexpected observations, which 
have been made for nearly two years at the menagerie, the most 
important of which, in a physiological point of view, is, undoubtedly, 
that which demonstrates the development of the generative power in 
animals which have not yet arrived at their definitive form. These 
observations have been published in the ‘Nouvelles Archives du 
Muséum’ (tome ii. pp. 265-292, pl. 10). 
I now take the liberty of submitting a summary account of some 
experiments to which I was led by the study of the facts just 
indicated. The atrophy of the branchial tufts and their gradual dis- 
appearance being the first signs of the metamorphosis which is going 
to take place, I have endeavoured to provoke a change in the mode 
of respiration by obliging the animals to make use of their pulmonary 
organs. I made at first some fruitless experiments, consisting partly 
in gradually diminishing the quantity of water in which the axolotls 
were kept, so as to leave them, after a certain time, nothing but a 
layer of damp sand, and partly in arranging in their aquarium a 
broad shelter, which enabled them to live alternately immersed and 
out of the liquid. 
To obtain any result there was another experiment to be made. 
It was necessary to destroy the branchiz, in order to ascertain 
whether, when rendered compulsorily animals with a pulmonary 
respiration, the axolotls would undergo the modifications which I 
have enumerated. 
Accordingly, on the 4th of July 1866, I completely removed the 
three branchial stalks on the left side in two axolotls, and those of 
the right side in a third; then, from the 14th to the 28th, I cut 
off every week one of the branchial stalks of the opposite. side. 
At this last date the axolotls would have been entirely deprived of 
the branchie if, during the twenty-four days which had elapsed. 
since the first operation, the astonishing power of regeneration with 
which the Urodelous Batrachia are endowed had not caused the 
commencement of a reproduction of the organs which had been re- 
moved. Therefore, in order to keep the axolotls in the state in 
which I wished to place them, so that I might appreciate the results 
of the experiment, I cut away successively, on either side, the new 
branchial stalks as soon as they began to project sufficiently to be re- 
moved by the scissors. From the 28th of July 1866 to the 24th of 
May 1867 (that is to say, a period of ten months), I was obliged 
to operate, either on the right or left side, three, four, or even five 
times. During the winter the reproduction was much slower. 
On the 10th of August 1866, I cut off the three branchial stalks 
of the right side of six axolotls, and, wishing to exert a more general 
and rapid action, on the 17th also the three branchie of the left 
side. As in the other cases, there was scarcely any hemorrhage, 
