258 DR. MARTIN BARRY ON THE CORPUSCLES OF THE BLOOD. 



Fig. 129. Ox ; foetus of eighteen or twenty inches. Objects from the retina, as 

 seen after the addition of acetic acid. (See the description of the fol- 

 lowing figure.) 



Fig. 130. From the same foetus. Elements of the retina, formed of corpuscles, 

 having the same appearance as corpuscles of the blood, a, j3, y. Are 

 such corpuscles, passing into globules, a. They have undergone but 

 little change. /3. Two or more pellucid points are seen in each cor- 

 puscle (par. 154.). y. The globule is now seen to be composed of 

 discs. ^. A cell, the nucleus of which consists of several discs, g. Cell 

 rather larger than that at S. Its nucleus, vrhich had a similar appear- 

 ance, is in outline. ^. Cell, the nucleus of which was surrounded by a 

 space more pellucid than the rest of the cavity of the cell. The whole 

 in outline. ??. Cell, in the nucleus of which are seen five discs. The 

 cavity or depression in one of these was very large ; and probably in- 

 dicated the situation of the orifice in the membrane of the cell. 0. Very 

 large cell. Its nucleus consisted of two parts. One of these was dark, 

 and globular in form. The other part surrounded that just mentioned, 

 and consisted of many globules. Each of the globules (in both parts) 

 was composed of discs, which were circumscribed by a delicate mem- 

 brane. The whole nucleus, also, was similarly circumscribed. /. Spin- 

 dle-shaped object, composed of discs, possibly representing an altered 

 state of a globule such as y, — the first change being seen at «. When 

 passing into the elements of the retina, corpuscles having the same 

 appearance as corpuscles of the blood seem to continue longer of a 

 flattened form than is usual elsewhere ; y, for instance, being rather 

 orange-shaped than globular. All the nuclei (^, g, ^, ri) were circum- 

 scribed by a delicate membrane. 



Fig. 131. Tadpole, 4 J'". Objects derived from corpuscles having the same appear- 

 ance as corpuscles of the blood, entering into the formation of the 

 elements of the retina. (The transition observed, though not repre- 

 sented in the figure.) 



Fig. 132. Tadpole, about 5 J'". Outline of corpuscles having the same appearance 

 as slightly altered corpuscles of the blood ; as seen entering into the 

 formation of the spinal chord. In one of these corpuscles, are deli- 

 neated the objects which were seen surrounding the nucleus. (Dilute 

 spirit.) 



Fig. 133. Ox ; foetus of 5 J inches. From the cortical portion of the brain, in which 

 objects such as those in the figure were observed in large numbers, — 

 often seen to be flattish in their form. They were all more or less red, 

 some blood-red, the difference being in some degree represented by the 

 shading ; all were either discs themselves, or composed of discs ; and 



