Dr. Young’s Lecture 
76 
discover ramifications from some of these points, upon and 
within the substance of the lens, (Plate VI. Fig. 48.) generally 
following a direction near to that of the fibres, and sometimes 
proceeding from a point opposite to one of the radiating lines of 
the same surface. But the principal vessels of the lens appear 
to be derived from the central artery, by two or three branches 
at some little distance from the posterior vertex ; which I 
conceive to be the cause of the frequent adhesion of a portion 
of a cataract to the capsule, about this point : they follow 
nearly the course of the radiations, and then of the fibres ; 
but there is often a superficial subdivision of one of the radii, 
at the spot where one of them enters. The vessels coming 
from the choroid appear principally to supply a substance, 
hitherto unobserved, which fills up the marginal part of the 
capsule of the crystalline, in the form of a thin zone, and 
makes a slight elevation, visible even through the capsule. 
( Fig. 49 — 51 . ) It consists of coarser fibres than the lens, but 
in a direction nearly similar ; they are often intermixed with 
small globules. In some animals, the margin of the zone is 
crenated, especially behind, where it is shorter : this is observ- 
able in the partridge ; and, in the same bird, the whole sur- 
face of the lens is seen to be covered with points, or rather 
globules, arranged in regular lines, (Plate VII. Fig. 52.) so as 
to have somewhat the appearance of a honeycomb, but towards 
the vertex less uniformly disposed. This regularity is a suffici- 
ent proof that there could be no optical deception in the appear- 
ance; although it requires a good microscope to discover it dis- 
tinctly : but the zone may be easily peeled off under water, 
and hardened in spirits. Its use is uncertain ; but it may possibly 
secrete the liquid of the crystalline ; and it as much deserves the 
