Sorensen, Study of Epiphysis and Roof of Diencephalon. 3 5 



outline, but the lens changes from concavo-convex to double- 

 convex, and at first the optic vesicle presents a double-convex 

 outline in section, which alters to concavo-convex. 



In concluding his article McKay compares the forms which 

 he studied and those described by Spencer, and gives the fol- 

 lowing points which are similar, or dissimilar : 



(1) A scale is modified to form a cornea in Grammato- 

 phora, this being similar to such forms as Calotes, Varanus, etc. 



(2) The lens is double-convex in outline, a point which ap- 

 pears to be common to nearly all the forms in which the eye is 

 known. 



(3) That the shape of the lens in the youngest stages of 

 Hinulia is similar to the lens in Cyclodus, the eye in the latter 

 being in a transitional state. 



(4) As in some of the forms (Varanus, etc.) pigment is 

 developed in the lens, so also in Hinulia slight pigmentation is 

 present. 



(5) The lens is composed of columnar nucleated cells. 



(6) Retina. The columnar cells called rods are present. 



(7) Nuclei are present in the rods in the later stages, a 

 point not ascertained by Spencer in his higher forms. 



(8) That the pigment is disposed in horizontal layers in the 

 rods, and that where the rods join the lens the pigment reaches 

 through the whole thickness of the retina. 



(9) That a humour exists in the optic vesicle. 



(10) That the rods have processes attached to the lower 

 extremities. 



(11) That spherical nucleated cells exist in Hinulia similar 

 to those in Hatteria. 



(12) That the molecular layer (if such it be) of Hinulia is 

 placed in a very different position to the molecular layer of Hat- 

 teria and Varanus. 



(13) That layers of spindle-shaped elements exist, which 

 have no correspondence to any of the elements in Hatteria or 

 Varanus. 



(14) That layers of triangular-shaped elements exist which 

 have no correspondence to anything in Spencer's form. 



