


1891. The Vermilion-Spotted Newt. IIOI 
Conclusions.—So far as I have yet been able to learn from the 
opinions of others or my own observations, no explanation has 
offered itself for the bright color of the terrestrial, red form. The 
color renders it exceedingly conspicuous, and there is no counter- 
balancing compensation in sexual selection, for the red form is 
sexually immature. The olive-green or viridescent color of the 
adult does render it inconspicuous in green terrestrial or aquatic 
vegetation; they are sometimes found in large numbers in water 
nearly devoid of vegetation, however. 
With reference to the change from the aquatic to the terres- 
trial life, and later the return to an aquatic life, there is perhaps 
a more satisfactory explanation or hint. Diemyctylus conforms 
in habits with the vast majority of batrachians in going to the 
water to lay its eggs. Still conforming to the habits of the 
group, the larvæ, on reaching a certain stage of development, 
absorb their gills, leave the water, and become air-breathers. It 
is not the purpose of this paper to attempt a discussion of the 
causes which led, in the course of evolution, to the assumption of 
an aërial for an aquatic existence by the Diemyctylus and many 
other Batrachia. It must be assumed that the reasons were 
sufficiently potent. Two will occur to every one conversant with 
the breeding places of the batrachians,—the danger of the drying 
of the water, and the limited amount of food. 
With but few exceptions, the preparation for reproduction 
requires the terrestrial forms to again enter the water, and the 
life becomes for a greater or less time once more partially aquatic, 
A partial return to an aquatic mode of respiration, and the taking 
in of water by the pharyngeal movements described above, is by 
no means restricted to Diemyctylus, but it may be seen in such 
highly terrestrial forms as the little brown tree-toad (Hyla 
pickeringii) and the yellow-spotted salamander (Amdlystoma 
punctatum). It appears as if the surroundings of larval life, and 
the necessity for respiration brought about by the prolonged stay 
under water required for fertilization and ovulation recalled by a 
kind of organic memory the mode by which respiration was 
accomplished in larval life. 


