DR. MARTIN BARRY ON THE CORPUSCLES OF THE BLOOD. 257 



the part was more advanced, the surrounding globules had very much 

 disappeared ; and the corpuscles were in polyhedral forms. 



Fig. 124. Tadpole, about 5'". Corpuscles having precisely the same appearance as 

 blood-corpuscles, passing into the elements of the optic nerve. Taken 

 from various parts of a fasciculus of incipient fibres in the immediate 

 neighbourhood of the eye-ball, which the fasciculus was seen to enter, 

 a. The corpuscles in question arranging themselves in a line. These 

 are all in outline except one. Immediately within their membrane 

 was red colouring matter. This surrounded a pale globular object 

 (nucleus), in which were discs. In the red colouring matter, there 

 were seen very minute globules, having a high refracting power. These 

 were of a brilliant red colour. Many of them appeared to be under- 

 going division. They presented the appearance of a rose. These 

 globules occupy the situation of such as are seen, in many instances, to 

 exhibit molecular motions in corpuscles of the blood. — All the other 

 objects in the figure were composed of discs; and all were red, the 

 colour becoming paler in the more advanced. 



Fig. 125. Tadpole, about 7'". Portions of the optic nerve, forming out of corpus- 

 cles having the same appearance, as corpuscles of the blood. Quite 

 red. Almost entirely in outline, a. The discs into which the nuclei 

 of the said corpuscles had passed, were arranging themselves in some- 

 thing like lines ; and they presented discs in their interior, as in the 

 more finished disc of this object. j3. From a part of the same nerve, 

 more advanced. This object is a tube, at the periphery of which there 

 were seen discs coalescing. These discs presented discs in their inte- 

 rior, corresponding apparently to the minutest of those in the object a. 

 Pellucid points, apparently orifices, were seen here and there ; and they 

 seemed to communicate with the exterior of the incipient tube. (Dilute 

 spirit.) 



Fig. 126. Ox; foetus of eighteen inches. From the retina. Two corpuscles having 

 the same appearance as corpuscles of the blood, a. But little changed. 

 |S. Orange-shaped ; a large orifice in the situation of the original de- 

 pression (which existed when the corpuscle was a disc). Two pellucid 

 points on one side (par. 154.). (Dilute spirit.) 



Fig. 127. Ox; foetus often inches. From the retina. Two altered corpuscles 

 having the same appearance as corpuscles of the blood, a. The orifice 

 is very large; but single. |8. There exist two orifices (par. 154.). 



Fig. 128. Sheep {Ovis Aries, Linn.) ; foetus of eight inches. Corpuscles having the 

 same appearance as corpuscles of the blood, passing into globules for 

 the formation of the retina. See the description of fig. 130 ; the letters 

 denoting similar objects in both figures. 



