THE BATRACHIA OF NORTH AMERICA. 



221 



])nscles for wliicli Amphiiima is noted. Three gill-slits are open, of 

 which the two posterior become closed in the adult. The eyes appear 

 to better advantage than later in life. 



"The finding of these young nearly ready for active life in such an 

 unexi)ected situation suggests some interesting problems. At what 

 period of their development are these eggs deposited"? If at an early 

 period, the mother must incubate them for a considerable time. If at 

 a late period, why should they be placed in such a situation ? In either 

 case it appears to be quite probable that they are fertilized before they 

 are deposited. Again, how are the eggs in such a dry situation saved 

 from being thoronghly desiccated? They are, I think, kept moist by 

 the body of the mother as she lies coiled around them. My remem- 

 brance of her as she lay when first exposed is that she was much 

 plumper than she now appears in alcohol; and when she was laid down 

 on the office floor every spot she touched was made wet. The source of 

 this water I do not know; but it appears probable that it came from the 

 numerous glands that fill the skin, and that the mother makes nocturnal 

 visits to the water to lay in supplies." 



Fig. 56. Ainphiiima means. Three eggs, with embrjos iu different positions. From Haj', American 

 Naturalist, 1888. 



The Amphiuma presents towards the salamanders the nearest affinity 

 to the DesmognathidiTB. The pedunculate occipital condyle and atlan- 

 tal insertion of the temporal muscle are the same in both, and are re- 

 lated to a similar form and probably similar use of the muzzle. By 

 this arrangement the temporal muscle lifts the entire head by its inser- 

 tion in the lower jaw, thus taking the place of cervical muscles. It can 

 thus use the muzzle as a lever to burrow in mud and stones. Amphiuma 

 means also resembles the species of Desmognathus in the possession of 

 a chirrup or whistle. I do not know of another American salamander 

 which possesses a voice. The eggs in both genera are laid in a rosary. 

 I suspect that Amphiuma is a type which has degenerated from a sala- 

 mander like Desmognathus, but which possessed an ethmoid bone. 



