354 H. M. BERNARD. 
double movements probably playing some part in bringing 
about the invagination depicted in Diagram III, an invagina- 
tion which, as above insisted upon, must have included the 
lens. Whether the eyeball formed by this invagination ever 
moved with any degree of freedom under the cornea may be 
doubted ; the fibrous connection persisting in the ligamentum 
annulare was almost certainly strong, and may well have been 
rigid from the first. Certain it is that the movements of the 
eye asa whole, i.e. of the ocular invagination together with 
the skin above it (cornea), not only gave rise to the conjunctival 
folds by which the eye is suspended in the skin, but also ren- 
dered the directive adjustment of the lens by contractile fibrils 
unnecessary. As is well known, fibrils for the movement of 
the lens (“ m. retractor lentis ”—Beer) still persist in the eyes 
of the bony fishes, not only for the adjustment of focus, but 
also, according to Beer,! for slight changes in the direction of 
the line of vision. It is in keeping with these facts that the 
eyeball itself in the fishes is much less moveable, and in this 
respect also more primitive, than it is in the higher Verte- 
brates. We shall have presently to note other primitive 
features connected with the eyes in the bony fishes. 
On the isolation of the lens and the consequent abstraction 
of a large portion of the palisade layer from the front of the 
ocular globe, we may assume that this layer was regenerated, 
as shown by dotted lines in Diagram IV. 
The aqueous chamber developed as a space among the fibrous 
tissue forming the neck of the invagination: it would thus 
be morphologically a lymph space in the cutis. I have indi- 
cated the splitting apart of the fibres in this place in Diagram 
III. The aqueous chamber would thus from the first be quite 
distinct from the vitreous chamber, which was primarily a cleft 
in the epidermis (see below). 
The iris could be developed by the thinning away of the 
fibrous substance above the lens, and its radial contraction 
away from the optic axis. This contraction may be supposed 
to have given rise originally to the ciliary processes, as shown 
1 « Pfliig. Arch.,’ Bd. liii, 1894. 
