THE INDEPENDENT ORIGIN AND DEVELOPMENT 
OF THE CRYSTALLINE LENS 
CHARLES R. STOCKARD 
From the Department of Anatomy, Cornell Medical School, New York City 
WITH TWENTY-EIGHT TEXT FIGURES AND TWO PLATES 
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a Is the origin of the lens from the ectoderm dependent upon a contact 
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b Is the lens-plate or lens-bud capable of differentiating into a lens with- 
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¢ Does the size of the optic cup regulate the size or shape of its associated 
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d Is the optic vesicle, normal or defective, always capable of stimulating 
lens formation from the ectoderm at some stage of its development? ... 405 
e May the optic vesicle cause lens-formation from ectoderm other than 
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f Does a deeply buried eye have the power to regenerate or form a lens 
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5 Discussion of previous observations and experiments..................... 412 
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INTRODUCTION 
The crystalline lens normally arises in the embryo from ectoderm 
overlying the optic vesicle and continues its development in 
close association with the optic cup. This fact suggests that 
some correlation exists between the manner of development of 
the optic cup and the optic lens. In case such a correlation does 
exist, to what extent is the optic vesicle and cup responsible for 
the origin and subsequent development of the lens; and, on the 
other hand, what influence, if any, does the presence of the lens 
i 
