ON CHANGE OF MEXICAN AXOLOTL TO AN AMBLYSTOMA, 351 



water was gradually diminished, and during tliia time the first changes 

 in the animal appeared : The gills began to shrivel. At the same time 

 the creature showed a striving to reach the shallow places. The 4th of 

 December it betook itself wholly to the land and crept away into the 

 damp moss which I had placed on a bed of sand in the highest part of 

 the bottom. This was followed, by the first molt. Within the four days 

 from December 1 to 4 a striking change took place iu the exterior of I. ; 

 the gill-tufts shriveled almost entirely together, the crest on the back 

 vanished completely, and the hitherto broad tail assumed a rounded 

 form similar to a land salamander's tail. The grayish-brown color of 

 the body gradually changed to blackish j here and there white spots 

 came out, faintly marked at first, and growing more distinct. 



" When, on the 4th of December, the Axolotl crept out of the water, the 

 clefts of the gills were still open, but they gradually closed, and iu about 

 eight days they were no longer to be seen and were grown over with a 

 skin. 



"Of the other larvsB, at the end of November (that, is at the same 

 time when I. came to the surface of the water), three more were just as 

 strongly developed as I. — an indication that for them also the right 

 time had come for the hastening of the process. They were therefore 

 subjected to the same treatment. II. changed in fact at the same time 

 as I., and, precisely like it, had perfect gill-tufts when it was placed in the 

 shoal water, and after four days had almost completely divested itself of 

 these. He went upon the land j and then followed, in the course of about 

 ten days, the growing over of the gill-clefts and the complete assumption of the 

 salamander'^ s form. During this last time the animal took food, but only 

 when he was urged. 



"With III. and IV. the change went on more slowly. They did not so 

 frequently seek for the drier places, and generally did not expose them- 

 selves so long to the air, so that the greater part of January passed 

 before they took wholly to the land. Yet the drying of the gill-tufts 

 required no longer time than I. and II. The first molt also followed as 

 soon as they crept upon the land. 



"V. showed much more remarkable deviations in the transformation 

 than III. and IV. As this individual from the beginning appeared much 

 more feeble than the others, and also staid behind remarkably in its 

 growth, this was by no means surprising. It required fourteen days 

 instead of four to carry the change so far that it could leave the water. 

 It was of quite peculiar interest to watch the condition of this individual 

 during this time. As may be inferred from its delicate nature, it was 

 more sensitive than the others to all outward influences. If it was ex- 

 posed to the air too long it took on a lighter color. Besides it gave 

 off a peculiar odor, similar to what salamanders diffuse when they are 

 alarmed or endangered. As soon as these appearances were noticed, it 

 was immediately put into deep water, where it dived under at once and 

 gradually recovered again. Then the gills always unfolded again. The 



