No. I.] DESMOGNATHUS FUSCA. 233 



each morning and night. He was then "marooned" for a 

 week or so in a jar containing nothing but some damp earth 

 and food. After his restoration to his mates in the aquarium 

 he appeared as active as any of them. 



These experiments were carried on early in 1892 and they 

 are of peculiar interest from the fact that in the many speci- 

 mens dissected no trace of lungs were ever seen, nor are gills 

 present except in the larval stage. The epithelium of the 

 mouth cavity, except the tongue, is of a ciliated columnar 

 character; the oesophagus is likewise ciliated, the movement 

 being in a caudal direction. Gage (Proceedings of the American 

 Association for the Advancement of Science, Vol. XXXIX, 

 1890, p. 338) finds that " In all forms of Amphibia and in all 

 stages after the complete disappearance of the food yolk, 

 ciliated epithelium is absent from the mouth when the respi- 

 ration is mostly aquatic, and water is frequently taken into the 

 mouth ; and that in forms with mostly aerial respiration, where 

 water is rarely taken into the mouth, the mouth is lined with 

 a ciliated epithelium." 



In the aerial respiration of the Desmognathus the floor of 

 the mouth is alternately raised and lowered very rapidly, while 

 during his enforced aquatic sojourn it was noted that he raised 

 the floor of his mouth and kept it so for a long time. It is 

 not impossible that in this form aquatic respiration may pre- 

 dominate from late fall to early spring, and aerial during the 

 summer months. If this be the case we might expect the 

 ciliated or non-ciliated condition in accordance with what has 

 been said above.^ 



Although the neurology of the urodeles has been enriched 

 by valuable contributions from eminent investigators both in 

 this country and in Europe there has been scarcely any appli- 



1 In the Anatomischer Anzeiger for January, 1894, No. 7, pp. 216-220, under 

 the title of Lungenlose Salamandriden, Dr. Harris H. Wilder states that the 

 Desmognathus fusca may live some forty-eight hours away from the water, in a 

 box filled with fresh grass. He does not comment upon the oral or oesophageal 

 epithelium, but his figures show it as columnar and non-ciliated. My own experi- 

 ments show that these salamanders will live for weeks in a small jar, with no 

 other water than that present in a small piece of moist sod left in the jar with 

 them ; a small amount of water being added from time to time to prevent its 

 drymg up. 



