82 CALIFORNIA ACADEMY OF SCIENCES. [3D Ser., 



and cilia in abundance. All the others were without 

 either. 



Again, the specimen which I have already mentioned as 

 having remained under water an hour after I began watch- 

 ing him before he came to the surface, I found to possess 

 an abundantly ciliated oral epithelium. This case seems to 

 be in striking opposition to Gage's conclusion that " in all 

 forms of Amphibia and in all stages after the complete dis- 

 appearance of food yolk, ciliated epithelium is absent from 

 the mouth when the respiration is mostly aquatic, and water 

 is frequently taken into the mouth " (Gage, '90). But I 

 must say that since this specimen's skin was fully papillated 

 and its tail-fin was much reduced, I should not have con- 

 sidered it to be strictly aquatic had it been brought to me 

 without information as to where it was captured. Having, 

 however, seen it remain at the bottom of the stream for so 

 long a time, and having convinced myself by careful ob- 

 servation that it was regularly carrying on the pharyngeal 

 respiration, I can see no sufficient grounds for supposing 

 that it had been anything else than a water dweller for six 

 months or more, at least, i. e., during the whole winter, 

 spring, and summer thus far, viz., to June 29th, the time of 

 writing. And this is the more probable from the fact that 

 the animals do undoubtedly return from the smooth to the 

 papillated condition without leaving the water. I speak of 

 this more fully elsewhere. 



I have also found the mouth epithelium ciliated in several 

 females which I have no reason for supposing less aquatic 

 than several others in which such cilia were not present. 

 But it must be borne in mind that absolute certainty, either 

 as to how long or how constantly particular animals have 

 been in water, is possible only upon direct observation, or 

 from having kept them under conditions that would preclude 

 the possibility of their leaving the water. 



I find, after having examined a large number of cases, 

 no exception to Gage's conclusion, "that in forms with 

 mostly aerial respiration, when water is rarely taken into the 

 mouth, the mouth is lined with a ciliated epithelium." 



