EYE OF LUCIFUGA. 



209 



pigment cushions on the eye, or in extra ocular regions at times in contact with 

 the sclera, at other times in the orbital fat some distance removed from the eye. 



While, other things being equal, we find a progressive decrease in the size of the 

 eye with age, we do not find that individuals of the same size have eyes of the 

 same size. On the contrary, the eyes of individuals of approximately the same 

 length may be very different in size and, as we shall see later, in structure also. For 

 instance, of 4 young taken from the ovary of one mother and differing from each 

 other by not more than 2 mm. in total length, we have the eyes of two individ- 

 uals without a lens and the eyes of the other two with large lenses. The eyes 

 measure 272, 320, 384, and 416 p respectively, or, after clearing in xylol, which 

 permitted a more minute measurement, 260, 280, 375, and 425 (fig. 72, A). De- 

 tailed measurements of these eyes will be found in the following table: 



Measurements in //. of Eye of Female Litcifnga and of Four Young contained in her Ovary. 



f.v, as they were taken from the ovary ; y, cleared in xylol ; z, sectioned.] 



1 Lower embryo of right ovary. 

 a Upper embryo of left ovary. 

 3 Lower embryo of left ovary. 



4 Upper embryo of right ovary. 



s Vertical distance between inner margins of scleral cartilage. 



