144. FORMATION OF SHELLS OF ANIMALS, ETC., 
confused and ill defined. The exact form of the lens in 
these fishes, with the arrangement of its fibres, as given at 
the commencement of this description, can be best seen in 
eyes which have been kept in glycerine for several months. 
In some specimens thus treated, the striz in that part of 
the converging fibres near to the equator of the lens can 
also be seen, but not sufficiently to give any idea of their 
true structure, and nothing definite is observable of the 
clear viscous, albuminous particles so distinct in the per- 
fectly recent lens, these having become granular and 
amorphous. I may mention, that in all the examinations 
I have made of the lenses of these fishes, 1 have never met 
with the layer of nucleated cells seen in the eyes of mammals 
close to the deep surface of the capsule; in some stances 
there have been regular corpuscles, but these were found 
only occasionally, and without any definite arrangement 
or situation; and I have no doubt but that they are acci- 
dental, and are only the white corpuscles of the blood 
which have escaped from the vessels ruptured in removing 
the lens from the eye, especially as I have found the red 
corpuscles with them. Having now described these parts 
as minutely as appears to me to be necessary, also the 
manner of examining the lens, both in its recent and pre- 
served states, I will consider its development in relation 
to the process of molecular coalescence. Now, connected 
with the albuminous particles situated on the surface of 
the lens, between it and its capsule, the following facts 
require notice. First, their extremely variable size, the 
smallest being too minute to admit of accurate measure- 
ment, the largest, in the undistended condition, being 
about s5/59th of an inch in diameter, and the rest being of 
all sizes intermediate between these extremes. Secondly, 
the perfect resemblance of these particles one to another 
