THE BLOOD. 65 



encountered by Mr. Gulliver * in clots of fibrin in man and 

 other mammalia, and are alike to be found in them, whether 

 the clots are formed in the body after death, or in blood 

 abstracted from the system during life. 



These corpuscles, of a very peculiar structure, as will be 

 seen hereafter, Mr. Gulliver has described and figured with 

 extreme accuracy ; and he has styled them " organic germs," 

 " primary or nucleated cells," and as capable of further deve- 

 lopment if placed in circumstances favourable to their growth. 

 Mr. Gulliver, however, would appear to have been quite 

 undecided as to their real nature, and whether they were not 

 to be regarded as identical with the " fibrinous globules " of 

 Mandl. 



These peculiar bodies I have myself met with in fibrinous 

 clots which were found in the heart after death ; and I have 

 no hesitation in asserting that they differ, in every essential 

 particular, from the fibrinous globules of Mandl, which are 

 identical with the colourless corpuscles of the blood. 



The size of these corpuscles is subject to the greatest pos- 

 sible variation ; they are frequently smaller than the white 

 globules of the blood, but very generally three or four times 

 larger ; their form is also irregular, but inclining, in those 

 which I have examined, to the spherical. They consist of 

 two parts, of nuclei and envelopes : the nucleus is of an 

 irregular outline, and not usually well defined without the 

 aid of re-agents ; its bulk is about the one fourth or one fifth 

 of that of the entire corpuscle; the envelope, in all the 

 globules which have fallen under my observation, has been 

 compound, that is, made up of several vesicles concentrically 

 disposed, the one within the other. (See Plate TV. Jig. 3.) 



The appearance presented by these objects bears a close 

 resemblance to the vesicles of certain species of Algse, of the 

 genus Microcystis or Hcematococcus, these being likewise each 

 composed of several concentrically arranged membranes or 

 vesicles. 



Now, what is the opinion which ought to be entertained 



* See translation of Gerber, p. 31., and Appendix, p. 16. 



