DR. MARTIN BARRY ON THE CORPUSCLES OF THE BLOOD. 237 



opinion of this eminent observer, that the fibres are elongated cells. The mode in 

 which the fibres seem to me to form out of cells, will be hereafter mentioned. The 

 first, and more important question is, what is the material furnishing the cells, and 

 therefore the fibres of the lens ? It is here needful to make a few preliminary re- 

 marks. 



166. Slices cut from the surface of the lens in the foetal Calf and Sheep, have 

 presented to me in the microscope, not only red blood, but young blood-corpuscles, 

 as well as the parent-corpuscles from which they were escaping. Seldom have I had 

 so favourable an opportunity for observing the manner in which the blood-corpuscle 

 is perpetuated (fig. 141. ^ ^), and for making the observations I have now to mention, 

 — that the young blood-corpuscle has a peculiarly bright colour, and — though in 

 Mammalia — an elliptical form. The young corpuscle soon becomes round, though 

 at first it continues flat ; the latter no doubt answering an important end connected 

 with its motion in the vessels. 



167. Fig. 141. affords a proof that the diameter of the corpuscles usually seen in 

 circulation, is no criterion by which to judge whether red blood can make its way 

 into parts generally considered colourless. For, at a, a portion of vessel is filled with 

 corpuscles, having a diameter not much more than half of that usually ascribed to 

 them : the fact being that, besides the minuteness of the objects into which blood- 

 corpuscles may divide, the form of the corpuscles is susceptible of every change ; and 

 minute indeed must be the orifice they could not be made to enter, so attenuated is 

 the shape they sometimes assume. It may be also added, that I have observed a 

 capillary forming, the diameter of which measured only tqo'"^ which indeed was 

 about the size of some of those in fig. 141 : and I have seen objects having precisely 

 the appearance of blood-corpuscles, of less than tooo'"- Mere points too, are found, 

 having the red colour of the blood, and we have already seen that minute objects 

 exhibiting molecular motions, may be observed within corpuscles of the blood 

 (par. 128.) ; as well as that young corpuscles of the blood are met with, exhibiting 

 motions comparable to that called " molecular," and so minute indeed as to have the 

 appearance of " molecules" enlarged (par. 126.). 



168. Corpuscles having the same appearance as young blood-corpuscles, are also 

 seen within tubes— fig. 144. And this figure shows that, while the red colouring 

 matter was still present in some, it had disappeared in others, — the latter being re- 

 presented in outline only. — Other states of the corpuscles are observed, also within 

 tubes, as in fig. 149. They here exhibited the same division into discs which we 

 have found to take place elsewhere : and while some of the corpuscles undergoing 

 this division were blood-red, others were becoming pale. A farther change is met 

 with : the masses of discs, derived from such corpuscles, seem to be arranging them- 

 selves into lines, as if to form fibres (fig. 150.). 



169. I have seen red capillary vessels on the posterior surface of the lens. Here 

 the vessels radiated from central trunks, towards the margin of the lens. One of 



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