Charles R. Stockard 515 
from the experiments by proving that such results may occur under 
normal conditions and are, therefore, in no way attributable to the 
injury caused by the operations. 
The question of the localization of lens-forming material in a given 
ectodermal area is not answered by Bdellostoma, but I have shown in 
artificially produced cyclopean monsters in the Teleost that a lens may 
form from a region out of the usual lens-forming area, and that the 
size of the optic-cup regulates the size of the lens. So, in other fishes, 
just as in amphibians, we would not expect to find localized lens-forming 
regions in the ectoderm. 
I wish to express my indebtedness to Professor Bashford Dean for 
kindly placing at my disposal his complete series of Bdellostoma embryos. 
18 Stockard, C. R., The Artificial Production of a Single Median Cyclopean 
Eye in the Fish Embryo by Means of Sea-Water Solutions of Magnesium 
Chlorid. Arch. Entw.-Mech., XXIII, 1907. 
40 
