1088 The American Naturalist. [December, 
ence to these two forms: “ There are two forms of this subspe- 
cies, which have received the names of viridescens and miniatus 
respectively. These have been shown to be stages of one and the 
same animal; they are not distinguished otherwise than as sea- 
sonal forms, which may be by reason of the environment rendered 
permanent for a longer or shorter time” (p. 207). 
As seen by the above quotations, Say apparently made but a 
single species of the red and viridescent forms; but some later 
authors even placed them in different genera. Their great similarity 
= was, however, remarked upon by Storer and others. Finally, 
since the work of Baird in 1850 they have remained in the same 
genus, but have been by many considered as distinct species. A 
further study and more careful observation of living specimens, 
have, since 1850, indicated the probability, and finally showed the 
certainty, that the two forms were states of the same species 
(56—90). Furthermore, these observations not only showed that 
the red, terrestrial form changes to the viridescent, aquatic form, 
but, where the matter is discussed, it is assumed that the reverse 
may occur, the difference of coloration, roughness, etc., being 
dependent upon season, food, and environment (Hallowell, 56; 
Cope," 9, 87; Pike, ’86). 
While Say (’19) says the young is of a uniform orange color, the 
sentence immediately following that statement, “It is decidedly 
aquatic,” leaves one in doubt concerning his actual knowledge 
concerning the two forms. There is one author, however (Monks, 
’80), who distinctly intimates, although unable to prove, that the 
red form is a stage in the development of the Diemyctylus. Both 
Say and Monks are silent concerning the possibility of a return of 
the viridescent to the red coloration. 
In order to complete the chain in the life-history of the Diemy- 
ctylus, and to determine so far as possible its habits, structure, 
physiology, and transformations during the varying phases of 
aquatic and terrestrial existence, the writer has availed himself of 
every opportunity for investigating it during the last six years. 
The results of this study may, perhaps, best be given by com- 
mencing with the egg : 



