Sco” PROCEEDINGS OF THE NATIONAL MUSEUM, 161 
-_ete., intended for its food without perceiving it by sight or smell, but 
as soon as the food comes in contact with any portion of the skin, espe- 
_ cially of the head region, the sluggish movements are instantly trans- 
_ formed, and a stroke of the fins brings the mouth immediately in position 
for operations. 
I have not been able to raise the fishes from the egg. The youngest 
individual ever seen is represented in Fig. 7.* In this specimen the mem- 
branes of the fins were thin, the color cells were well formed and ar- 
ranged not unlike those of the young Gillichthys, Fig.12. Its movements 
were similar to those of the other gobies, and not at all sluggish like 
those of the adult. The favorite position is a standing or sitting one 
with the broad pectorals extending out at right angles tothe body. In 
this position the fish can, with a sudden stroke of its pectorals, move 
quickly and rapidly. In the old the fins are thick and smaller in pro- 
portion, and all the vivacity seems to have disappeared. The color has 
degenerated, or at least not developed in proportion to the growth of 
the fish. : 
The minute structure of the eye was not examined. It will be 
described in another paper. The eye and optic nerve have been isolated 
by treatment with 20 per cent nitric acid, and by simple dissection of 
alcoholic specimens. The lens is large in proportion to the size of the 
eye, which does not materially differ in size in the smallest and largest 
specimens examined. The optic nerve is very slender and long as com- 
pared with that of any of the other gobies, 
All the gobies are tenacious of life, especially the blind one. Several 
of the latter have been Kept in a half-gallon jar for several weeks with- 
out change of water, and others have been kept several months in con- 
finement in my laboratory. When the water becomes somewhat stale 
they frequently rise to the surface and use the surface of the water as 
a plane to which they attach themselves by means of their ventrals. 
It was my intention to study the development of the eyes, ete., of this 
| fish, and with this end in view I kept many specimens alive and made 
frequent trips to Point Loma to procure fresh individuals in order that 
too long confinement might not have impaired the reproductive funce- 
tion. They spawn in the latter part of May and June, but I have not 
found the eggs in nature. Those deposited in confinement would not 
develop, and attempts at artificial fertilization of freshly-caught indi- 
| viduals were not successful. An absence from San Diego prevented 
* During the summer of 1891 Mr. L. C. Bragg, of Coronado, found the eggs attached 
to the lower surfaces of the rocks under which the fish live. He kindly gave me 
several specimens from which the drawings of plate A, xviii were made. The zona 
| is seen in nature to expand enormously and become club-shaped. In this chamber 
the young are able to live long beyond the ordinary hatching period of fishes. The 
eggs are attached to the rocks in asingle layer by the network of threads surrounding 
the micropyle. The eyesdevelop normally, and those of Fig. 4 differ in no way from 
the eyes of other fish embryos. This offers a most striking example of degeneration, 
)}| The minute structure of these larval eyes will be described by one of my students, 
Proc. N. M. 92 ig! 
