358 H. M. BERNARD. 
is also accounted for. A comparison of the diagrams shows 
at a glance that, while the latter is simply a lymph space (cf. 
Fuchs’s diagram of the lymphatics of the eye!) arising within 
the connective tissue of the cutis, the former is an epidermal 
space, and is accordingly filled with slimy matter, presumably 
identical with that which gradually turns the cells of the rete 
mucosa into the horn cells. 
5. The shape and curious arrangement of the cells forming 
the lens, the gradual loss of their nuclei, and their progressive 
transformation into hard refractive matter as the centre is 
reached are simply explained by regarding them as the prickle 
and horny cells which formed at one time a primitive surface- 
lens, subsequently engulfed in the invagination. That these 
fibres are closely comparable with epidermal prickle-cells can 
be demonstrated under the microscope ;* they have all the 
known characters of such cells, in addition to their gradual 
decay and conversion into hard refractive matter. The pig- 
mented granules of the iris on the one hand and the vitreous 
humour on the other could obviously supply them with abun- 
dance of slimy matter for this purpose. 
6. I may be allowed again to allude to the arrangements 
of the blood-vascular loops as shown in the diagrams; to the 
ciliary process, which is accounted for as a simple mechanical 
result of the formation of the iris (cf. Diagrams III and IV) ; 
and to such structures as the pecten and processus falciformis, 
and the intra-bulbar blood-vessels still persisting in different 
eyes among the lower Vertebrates. 
In addition to the weighty evidence afforded by these purely 
morphological arguments, it is worth noting that the recent 
discovery of Wolff,? fully confirmed by Miller,‘ as to the re- 
generation of the lens in Triton from the iris, is in the main 
in accord with Diagrams III and IV. The details as given 
by these authors are, however, very curious. The outer of 
' Reproduced in Morris’s ‘ Treatise on Anatomy,’ 1893, p. 889. 
2 Cf. the first note, p. 357. 
3 * Archiv fiir Entwick. Mechan.,’ i, 1895. 
4 Eric Miller, ‘Arch. f. micr. Anat.,’ p. 23, 1896. 
