66 ORGANISED FLUIDS. 



in reference to the nature of these corpuscles ? Do they 

 really constitute an integral portion of our organisation ? and 

 do they circulate in the living blood ? or are they formed in 

 it after death ? The opinion of Mr. Gulliver that they are 

 primary, or nucleated cells, has already been referred to : 

 my own impression as to them is, that they do not constitute 

 an integral portion of our frame ; and that, whether they exist 

 in the living blood and circulate in it, or are formed in the 

 clot subsequent to decease, they are to be regarded as extra- 

 neous formations,, probably of an entozoal character. 



It does not appear that the envelopes of all the corpuscles 

 met with by Mr. Gulliver exhibited concentric stride, al- 

 though he describes some of them as possessing this striated 

 structure : Mr. Gulliver speaks also of cells three or four 

 times larger than the corpuscles, and capable of containing 

 the latter as nuclei. These I have not myself encountered. 



The corpuscles are not usually scattered equally through- 

 out the fibrinous clot, but frequently occur in groups, parts 

 of each clot being altogether free from the corpuscles. 



Acid re-agents, especially the sulphurous acid, will be 

 found useful in their examination.* 



BLOOD GLOBULES OF REPTILES, FISHES, AND BIRDS. 



The red globules of the blood of the reptile, the fish, and 

 the bird, have all certain characters in common with each 

 other, which serve to distinguish them from those of man 

 and the mammalia in general. The chief of these character- 

 istics are their form, their size, the presence of a nucleus, 

 and, lastly, their greater consistence. The compressed form 

 belongs to the red blood globules of all animals ; in the three 

 classes of reptiles, fishes, and birds, however, although the 

 globules possess this flattened figure, instead of being circular, 

 as in man and the mammalia, they are in outline elliptical ; 



* Since writing the above description, I have met with these concentric 

 corpuscles in connexion with the thymus gland which had been allowed 

 to remain in water for a few hours. 



