448 Miscellaneous. 



nor did any ill event supervene ; the cicatrization was rapid, and the 

 power of reproduction soon manifested itself. The following ampu- 

 tations were made at once on the six animals — on the right on the 

 2 1 St, and on the left on the 28th of September. 



The branchiae, after the second removal, were scarcely developed ; 

 and several of the animals operated upon began to acquire a new 

 aspect in consequence of the appearance of some yellow spots on the 

 skin. Two of these individuals became more and more spotted, lost 

 their crest, and finally became like the axolotls which had pre- 

 viously been transformed. The four other axolotls of the same 

 series, but especially two of them, presented some spots, without 

 any trace of metamorphosis ; their branchiae having acquired a slight 

 development, I amputated those of the left side on the 8th of March, 

 and those of the right side on the 5th of April. 



One of these axolotls continued spotted, but without any other 

 marked change ; there was scarcely any regeneration of its branchiae. 

 In the three others it was rather more evident ; and on the 24th of 

 May I cut off the branchiae on each side, and again on the 22nd of 

 June, little buds having been developed. 



Thus of six axolotls deprived of their branchiae, and in which care 

 was taken to oppose the regeneration of the lost parts, two became 

 completely metamorphosed in from four to five months ; and a third at 

 the end of nearly a year seems to have undergone the same changes ; 

 whilst the other three, after the same lapse of time, are in a state 

 which leaves the observer still uncertain as to the definitive result of 

 the experiment. It even seems probable that, like the three axolotls 

 of the first series, they will not be transformed, and that, conse- 

 quently, three only, out of nine deprived of their branchiae, have 

 passed from the larval to the perfect state. 



Such a proportion is much greater than that observed among the 

 individuals which have undergone no amputation. I indicate the facts, 

 without, however, wishing to draw the conclusion that the loss of the 

 branchial tufts is a condition very favourable to the accomplishment 

 of the metamorphosis. Moreover most of the transformations were 

 not preceded by functional disturbances resulting from the mutilations. 



Reverting now to the immediate results of the removal of the bran- 

 chiae, I may add that their resection, which would seem to imply the 

 production of formidable effects, and even to compromise existence, 

 maybe practised without inconvenience in a more expeditious manner. 

 On the 7th of June 1867, I removed the whole of the branchial 

 tufts from both sides at once of eight axolotls. Nothing particular 

 was afterwards observed ; and on the 22nd of June and 6th of July I 

 effected the removal of all the buds of new formation, which are 

 already beginning to be reproduced. 



These mutilations appear to me to have some interest. Here we 

 have, in fact, animals which, when deprived in a short space of time, 

 or even suddenly, of their organs of aquatic respiration, do not expe- 

 rience, at least as far as six out of nine of them are concerned, any 

 disturbance, and continue to live as if the branchiae had not been 

 removed. Coming no oftener than axolotls which had not been 



