PLATE XI. 
Fig. 
1 —Portion of back part of retina of bullock seen from the inner surface, 
to show nerve-fibres and layer of granular cells, which have been 
partially removed the better to show the fibres forming a layer, with 
1-12. x 600. 
2.—Fibrous layer of retina, showing varicose enlargements in the nerve- 
fibres, and also double-walled cerebral cells. x 450. From back 
part of retina of rabbit. L haye seen the same structures in the ox 
and the sheep, but not quite so distinctly. 
3.—Varicose fibres and clear oii-like cerebral cells from optic nerve in the 
pig, at its entrance into the eyeball. 
4,—ILayer of cells attaching retina to hyaloid membrane ; at first they are 
perfectly transparent, but soon become very finely granular. They 
are found in most animals, and are very distinct in the rabbit. 
5.—From turtle. ‘There are a few large flat cells with large irregular 
granular nuclei. x 450. Are they the caudate gangliform cells ? 
6.—From birds. a. Conoidal rods after some hours’ immersion in dilute 
spirit, showing, towards the czwer end, a conical process with a 
transverse mark as though breaking off here. &. Nerve-fibres from 
anterior part of retina of Cochin cock; after being forty-eight 
hours in dilute spirit, they formed a complete layer imbedded in the 
granular ceils; many of the fibres could be traced for a considerable 
distance, others were much shorter as though terminating at various 
points, all were more or less varicose ; the dilations showing double 
walls, and with them were some double-walled cells. c. Delicate 
cells, which are during life, or immediately after death become, 
minutely granular; they are very abundant in all birds. d. Perfectly 
transparent cells, which soon become very large and irregular in size 
and shape, probably from pressure and overlapping each other; they 
appear to form a layer between the retina and hyaloid; these are 
from the canary bird; they are not larger in the goose or turkey 
than in this little bird. x 450. 
7.—Capillary vessels of human retina; the artery from which they are 
given off measured 1-100 of an inch in diameter; the capillaries 
not more than 1-4000; washed with dilute liquor potasse, which, by 
erie the nerve-structures, renders the congested vessels very 
istinct. 
8,—Terminal vessels in human retina. They form a series of loops a little 
distance from the ora serrata. a. Ciliary processes. 0. Loops of 
capillaries joining to form trunk, e. 
9.—From frog. a. Very large cylindrical rods ; most, however, are of size 
seen at 6. Some of these are rather broader at their inner extremity 
than at the outer; many, but not all, are surmounted with a light- 
brown coloured globule, like those of birds and the turtle, but with 
much less colour; these are shown detached at c. They should not 
be shown with nuclei. d. Rods changed by the addition of water ; 
they curl up, become granular, and look like coffee-berries. e. Rods 
after addition of salt and water, which induces much less change than 
water. jf. In one frog I found three rods with conical inner ends, 
and transverse marks as here shown. g. A few large cells with 
pigment-granules, not much unlike some found in the brain, are seen. 
«K 450. ; 
