1889.] ^otcs on the Habits of Some Ainblystomas. 61 1 
the dilation of the hyobranchial apparatus, streams of water are 
drawn in through the nostrils, and this water is then expelled at 
intervals by the mouth. By keeping the salamander in a glass 
vessel containing water that has in it fine floating particles, and 
using a lens, one may readily see all the phenomena mentioned. 
The animal will remain under the water several minutes, some- 
times a quarter of an hour, breathing in this way. Then will 
occur motions indicating uneasiness ; large bubbles of air may 
escape from the mouth, and the animal will come to the surface 
and take in fresh air. It may remain there for some time, or 
may again go to the bottom and stir about as if trying to conceal 
itself The expulsion of the water through the mouth occurs in 
inicrostomum every eight to twelve seconds ; in tigrimun, every 
five or six seconds ; and in ptinctatiim, every four or five seconds. 
It is probably due to this pharyngeal respiration that they are 
able to remain imprisoned for so long under the ice of ponds. 
The Amblystomas shed the epidermal layer of the skin at fre- 
quent intervals. Whether this occurs oftencr when they arc in 
the water than in the earth, I do not know. The large specimen 
o{ A. tigrimun kept by me seemed to i)rcfcr to enter the water 
when about to exuviate. For some weeks during the past sum- 
mer while he w^as confined to the water, he shed his skin about 
every week. The skin comes off in one almost untorn piece, and 
floats about in the water like a shadow of the original. It seems 
never to be swallowed, as it is said to be in the case of the newt. 
The popular notion about these animals is that they are very 
poisonous. On the contrary they are perfectly harmless. Never 
but once have I succeeded in getting one of these animals even 
to attempt to bite. Once my large tigriiuiin, tliinking that some- 
thing was being offered him to cat. sci/.ctl my little finger. His 
teeth could scarcely be felt. K\cii if thc\' should penetrate the 
skin, there is no poison secreted that could enter the blood. 
These animals are not averse to being handled. I have 
thought that the small-mouthed salamander likes to be rubbed 
along the back with the finger or a straw. When thus rubbed, I 
have seen it lift its tail high in the air and wave it to and fro in a 
ludicrous way. 
