ORIGIN OF MONSTERS 509 



of the eye. The significance of this retinal fragment is at once 

 recognized when the condition of the whole eye is considered. 

 On following the sections posteriorwards the eye more and more 

 appears to be oval in shape. More posteriorly yet, the eye 

 widens out enormously (fig. 67) while the brain is at this point 

 very distorted and strikingly small in size. A few sections 

 further posterior^, the shape of the eye is still practically the 

 same, but its size has diminished somewhat while that of the 

 brain has increased. The latter which is now in the region of 

 the optic lobes is very distinctly bilobed, the right hemisphere, 

 although somewhat distorted, is, however, complete, while of the 

 left one about a half is wanting, the place of this lacking part of 



Fig. 47 Diagrammatic outline reconstruction of the cj-clopean eye of the 

 embryo in figure 12. 



the brain being occupied by the larger part of the eye, which at 

 this level is horse-shoe-shaped in cross-section. The very last 

 sections of the eye prove unmistakably that it is composite, for 

 its base consists of two separate optic cups. 



The nature of this eye is best understood from the diagram- 

 matic outline reconstruction which is attempted in figure 47. 

 It is a heart-shaped body with the apex directed frontalwards 

 and the base cerebralwards. 



The question now arises in what way this peculiar malforma- 

 tion came about. The intracerebral retinal fragment which was 

 deferred to above (fig. 66) as well as the shape of the eye and the 

 defects of the brain point to an answer which, I think, contains 

 a high degree of probability. Here, too, the injury sustained by 



