404 Charles R. Stockard. 
The possibility of the action of some substance given off by a 
distant optic cup is entirely aside, since other experimenters have 
claimed that when the optic vesicle or cup is In any way separated 
from the lens the latter organ begins to degenerate and usually 
disappears. 
Figs. 6, 7, 9, 10, 12, 13 and 21 and plate I, fig. 2, plate II, 
figs. 3 and 4, all go to show that in the fish embryo the lens-plate 
or lens-bud is capable of self-differentiation, finally forming a per- 
fectly transparent refractive body even though completely isolated 
from any other eye-like structure. 
¢ Does the Size of the Optic Cup Regulate the Size or Shape of its 
Associated Lens? 
Lewis (’07) has stated in his more recent paper on the lens that, 
“The lens is neither self originating nor self differentiating, but 
is dependent for its origin, its size, its differentiation and its 
growth on the influence of the eye.”? The writer had also inde- 
pendently been led to think from his first experimental study of 
eyclopia (’07), which was based on a limited supply of material, 
that the size of the lens varied directly with the size of the optic 
cup. He is now able to show that while normlly the lens and 
optic cup are properly adjusted as to size this is not by any means 
constantly true of ill-formed eyes. Here the size and also the 
shape of the lens is often greatly out of accord with that of the 
optic cup. In normal eyes the optic cup has a definite size and 
so does the lens. The sizes accord, yet this may be incidental or 
entirely without correlation, as is suggested by the fact that optic 
cups of unusual shape and sizeare not able to regulate the develop- 
ment of the lens so as to adjust it to their strange proportions. 
Many of the illustrations of cyclopean eyes given in the writer’s 
recent paper (’09) show misfits between the cups and lenses. 
Remarkable cases are also shown by figs. 9 and 10 and plate II, 
figs. 4 and 5, in which the lenses are clearly too large for the asso- 
’ ciated cups. Fig. 15 shows the two components of an incomplete 
cyclopean eye with one normally proportioned lens between them. 
This lens is scarcely large enough to function with the unusually 
