64 ORGANISED FLUIDS. 



back again to the lungs, they become dissolved, increasing by 

 their dissolution the amount of fluid fibrin circulating in the 

 blood, and which is deemed to be the true blastema. 



MOLECULES OF THE BLOOD. 



In addition to the red and the white globules, there exists, 

 as already mentioned, in the blood a third description of 

 solid constituent, the " molecules : " these are synonymous 

 with the " basin-shaped " granules of Yogel, the " globulins " 

 of Donne, and the " primary discs " of Martin Barry. 



The term molecule, or granule, is well suited to designate 

 these particles: for either appellation will serve to convey some 

 idea of their exceeding minuteness, and which is computed 

 rarely to exceed the ^ ~ n of an inch. They occur in great 

 quantities in the blood, either scattered singly throughout it 

 or agglomerated into small and irregularly shaped masses. 

 (See Plate I.jfig. 6.) The molecules are usually regarded as 

 the elements out of which the blood corpuscles are formed : 

 on this point, however, direct observations are still wanting. 

 It is more probable that the white globules are developed 

 out of them than the red, and this simply by their union or 

 aggregation.* 



PECULIAR CONCENTRIC CORPUSCLES. 



Besides the red and the white globules and the molecules, 

 which we have described as present in the blood, a fourth 

 species of solid corpuscle has been observed to occur in its 

 fibrinous constituent. These corpuscles have been repeatedly 



* Since the above few lines were written on the " molecules " of the 

 blood, I have repeatedly remarked, that in blood, on its first ab- 

 straction from the system, but few molecules were present, while in that 

 which has been withdrawn from the body for some time, they have always 

 abounded. This observation has led me strongly to suspect, that the 

 molecules do not exist in the blood in a free state, but that wherever and 

 whenever they are encountered, save only in the chyle, they are to be 

 considered as derived from the rupture and destruction of the white 

 corpuscles. 



