■ The Structure oj Colored Blood-Corpuscles. 283 



unless broken by the compression, which frequently happened, 

 and then the broken parts floated separately ; or, if they opened 

 at a single joint only, the whole of the ring would float along, 

 varying its figure occasionally from that of a portion of a circle, 

 which it would first assume, to a straight line, an undulated 

 one, or some other accidental incurvature.")* 



Hewson 2 declared the so-called globules in the blood of man 

 and all animals to be disks — " in reality, flat bodies," " as flat 

 as a guinea." The dark spot in the middle, which Father di 

 Torre had taken for a hole, he found " was not a perforation, 

 and therefore that they were not annular." He denied that 

 they were jointed, and inferred " they are not fluid, as they 

 are commonly believed to be ; but, on the contrary, are solid ; 

 because every fluid swimming in another, which is in larger 

 quantity, if it be not soluble in that fluid, becomes globular." 

 He also observed changes of shape ; for, speaking of the blood- 

 corpuscles of a lobster, he said : " But there is a curious change 

 produced in their shape by being exposed to the air ; for, soon 

 after they are received on the glass, they are corrugated, or, 

 from a flat shape, are changed into irregular spheres, as is 

 represented in Plate XII, No. 12 ;"8 and on turning to the 

 plate we find represented " angular," " rosette," and " stel- 

 lated " forms. He was the first who likened the appearance 

 of corpuscles, with their external surface corrugated, to that 

 of small mulberries. 



It would be impossible for me, as well as useless, to give a 

 list of all those who have described changes of form in red 

 blood-corpuscles since Hewson's time. Different shapes — 

 and some of them far more curious and irregular than those 

 I have described — have been observed, under many physio- 

 logical and pathological conditions, as well as on subjecting 

 the blood to the action of various chemical and physical agen- 



(1) Ibid V 256. 



(2) On tbe Figure and Composite on of the Ked Tartioles of the flood, cemiroi ly called 

 he Ked Globules " Philosophical Transactions. Vol. I XIII Fait II (1773). p. 3P3-323. 



(3) Ibid., p. 321. Opus postnumum, p. 19, 20 ; Collected Works, edited by Gulliver, c\t.' 

 291. 



