734 The American Naturalist. [September, 
sight or smell, but as soon as the food comes in contact with 
any portion of the skin, especially of the head region, the slug- 
gish movements are instantly transformed, and a stroke of the 
fins brings the mouth immediately in position for operations.” 
Here, again, it may be observed that this blind fish is prob- 
ably not older than the beginning of the Plistocene period, 
since we know that the coast of California has been rising since 
the Pliocene epoch, and therefore the coast lines have materi- 
ally changed since tbe end of the Tertiary. 
For a very full and elaborate account of the degenerate eyes 
of this blind fish we are indebted to Mr. W. E. Ritter, in an 
essay published during the present year. Besides the eyes he 
treats histologically of the integumentary sense papillae, and 
of the integument of this animal, giving a summary of his re- 
sults on pp. 96 and 97, which we in part reproduce. 
1. In the smallest examples of the blind goby studied, the 
eyes, though very small, are distinctly visible even in pre- 
served specimens, the lens being plainly seen. In the largest 
specimens, on the other hand, they are so deeply buried in the 
tissue as to appear even in the living animals as mere black 
specks, while in preserved ones they are, in many cases, wholly 
invisible. 
2. As is the case with rudimentary organs in general, the 
eye is subject to great individual variation in size, form, and 
degree of differentiation. 
3. The only parts of the normal teleostean eye of which n» 
traces have been found are the argentea, the lamina suprachor- 
oidea, the processus falciformis, the cones of the retina, the 
vitreous body proper, the lens capsule, and, in.one specimen, 
the lens itself. 
4. In the parts present the rudimentary condition of the 
organ is seen in the very slight development of the choroid; in 
the fact that the choroid gland is composed entirely of pigment; 
in the fact that the iris, though of fully the normal thickness, 
is almost entirely composed of pigment; with great propor- 
tional thickness of the pigment layer of the retina and the en- 
tire absence in it of anything excepting pigment; in the min- 
ute size of the optic nerve, and finally in the small size of the 
motores oculi. 
