27 



Axolotls had not long been in this position when the female 

 began to lay.* In depositing her eggs she climbed upon a 

 leaf of Vallisneria, clasping the narrow blade to her vent. 

 She then drew herself up a little higher, leaving the egg 

 behind attached on the leaf. As a rule, she moved upward, 

 but the eggs were not laid symmetrically or in any particular 

 order, but in no case did one touch another. There was no 

 attempt to fasten down the leaf over the egg, as is done by 

 Triton. The deposition was continued, with a few pauses, for 

 twenty-four hours, and then ceased. The eggs were 95 in 

 number. The female at once resumed her normal appearance. 

 The ovum when first laid was about the si^e of a flattened 

 mustard seed. It consisted of a blackish vitelline nucleus, 

 held in the centre of the vitelline membrane, which was so 

 remarkably transparent that every feature of the growing 

 embryo was most plainly discernible. The whole was 

 enveloped in an albuminous sphere which in a few hours 

 absorbed so much water that the whole attained the size of 

 a very large pea. 



I will not trouble you with a detailed account of the devel- 

 opement of the embryo during the four weeks which preceded 

 the hatching. I must say, however, that the whole process is 

 most interesting, being so easily observed owing to the trans- 

 parency of themedium. The segmentation of the vitellus began 

 to be apparent at the end of four or five days. Next appeared 

 the primitive median band, and soon the creature began to 

 assume a definite shape. In thirteen days the two branchial 

 buds made their appearance behind the head ; soon each of 



* Neither at this time nor any other, though I watched carefully, did 

 I see the supposed male show the slightest interest in the proceedings, 

 nor go through any of the evolutions described by M. Dumdril. My own 

 impression is that the eggs must have been impregnated previous to the 

 removal of the animals to my house, and that their deposition was 

 retarded by the sudden exposure to the much lower temperature of the 

 garden (The Axolotls had been kept in a hothouse). It is a matter of the 

 experience that the spotted Salamander, which is viviparous, can, when 

 deprived of access to water, delay parturition for a considerable time. 



