Alt — Histology 0} the Eye of Typhlotriton Spelaeus. 93 



is usually stated. The anterior surface is less curved 

 than the posterior one." It fills in ray sections almost 

 the whole space between the cornea and posterior sur- 

 face of the iris, and the retina, except at its posterior 

 pole where the retina has a funnel-like depression (cor- 

 responding to the optic papilla in man) in front of the 

 optic nerve. It consists of broad epithelial fibres with 

 large oval nuclei. While in man the capsular epithelium 

 reaches only a little ways back of the aequator of the 

 lens, in Typhlotriton it lines the whole of the lens cap- 

 sule. (See Fig. 8.) 



Whether there is any tissue, like the vitreous body 

 of man, in the eye of Typhlotriton I have not been able 

 to decide. There is in many of my sections a small 

 amount of amorphous tissue, stained slightly by eosin, 

 situated in the funnel back of the lens; but it is impos- 

 sible to state whether this is derived from vitreous body 

 or from disintegrated nerve fibres coming from the retina. 

 (See Figs. 1, 2, 9 and 10.) 



What I have stated thus far refers to the eyes of both 

 larvae and adults. As already mentioned, I can find no 

 material difference between the two states. If there is 

 one it must be in larvae considerably smaller than the 

 two which I had for examination. 



The only real difference I can find is that the adults 

 have eyelids and a conjunctival sac. (See Figs. 3 to 8.) 

 Two of my adult specimens have a small palpebral fissure 

 which is centrally located. Towards what might be 

 termed the outer and inner canthus the eyelids are united. 

 In these specimens the upper lid overlaps the lower one 

 in the palpebral fissure to quite an extent. (See Figs. 3, 

 6, 11.) Both lids contain the same small amount of sub- 

 cutaneous pigment. To both sides of the palpebral fis- 

 sure the union of the two eyelids is for a certain distance 

 an epithelial union only (see Fig. 13), but still further 

 outward this gives place to firm tissue union. The pal- 

 pebral opening can be of little use as far as the admission 

 of pictures from the outer world goes, especially since 



