6 10 The American Naturalist. [July. 
caterpillar had previously disappeared somewhat mysteriously, 
and now their fate was explained. I have fed this specimen in- 
sects, fresh beef, and tadpoles. Once it swallowed a mass of three 
or four grape skins ; but since he seemed to regard himself as no, 
prodigal son in dire extremities, he refused to accept any more 
such favors. He swallowed with ease a half-grown wood-frog. 
A smaller frog had lain about and become dry and stiff. It was 
offered to the salamander, who began to swallow it but soon re- 
jected it. A freshly-killed mouse was offered him and eagerly 
seized by the nose. He slowly swallowed it as far as the fore- 
legs. Then a lack of confidence in himself seemed to seize him, 
he grew uneasy, dragged the mouse about, and at length suc- 
ceeded in getting it out of his mouth. The mouse's head was 
covered with a sticky fluid, the secretion, no doubt, of the num- 
erous glands that fill the tongue of the salamander. Dr. Robert 
Wiedersheim states that he found a shrew in the stomach of a 
specimen of A. tigrinum that he dissected. One day my large 
salamander seized a good-sized spotted salamander by the tail, 
and only with difficulty was he made to release his hold. The 
amphibians appear to swallow one another without much regard 
either to relative size or to the ties of consanguinity. 
Reptiles at all periods of life, and amphibians after they have 
lost their gills, have been generally supposed to be wholly air- 
breathers ; unless the skin may take some part in aerating the 
blood. Recently, however, the Profs. Gage [Ainer. Nat., XX., 
233] have shown that the soft-shelled turtle enjoys an aquatic 
pharyngeal respiration, the mouth being filled and emptied by 
movements of the hyoidean apparatus. More recently [Schnce, 
Vn., 395] they inform us that the newt, Dicniyctylus viridcsccns, 
while under the water, both draws in and expels this clement by 
the mouth. In this process the walls of the mouth and i)h;u yiix 
serve as a place of exchange between the oxygen of the w ater 
and the gases of the blood. The same authors have observed 
water to be taken into the mouth-cavity of Cryptobranchus alle- 
ghaniensis, and expelled, partly at least, through the gill-slit. 
This pharyngeal respiration may be readily observed in the three 
species of Amblystoma under consideration. In all of them, by 
