The Structure of Colored Blood- Corpuscles. 269 



corpuscles. In the course of twenty-four hours or more — 

 though this occurs in by far the smaller number of prepara- 

 tions of blood examined — two or more adjacent colored blood- 

 corpuscles may, with a larger or smaller portion of -their periph- 

 ery, unite and form compound bodies, sometimes chains or 

 other strange shapes (fig. 3). 



Almost immediately on being ready for examination, a very 

 few colored blood-corpuscles show a light central vacuole. In 

 the course of the examination, a number of vacuoles, either of 

 different sizes, or all of the same size, may appear in a corpus- 

 cle. Usually, a vacuole is round or roundish, but it may as- 

 sume various irregular forms, — some of which, may perhaps 

 have resulted from a union of several, and the breaking down 

 of the separating walls, (see fig. 4. The three lower figures 

 show appearance of vacuolized corpuscles seen on edge). Vac- 

 uoles sometimes persist and sometimes, after a longer or shorter 

 continuance, suddenly disappear. They are either empty, or 

 else contain one or more granules. 



Soon after the corpuscles are studied, sometimes from the 

 first, a difference is noticeable as to the intensity of their col- 

 oration : some are paler than others. Gradually a larger num- 

 ber of corpuscles becomes pale, and the degree of paleness, too, 

 increases. There is a great difference in respect to the rapidity 

 of " paling " of colored corpuscles, in blood taken from differ- 

 ent persons, even in blood of the same person taken at different 

 times, and with different strengths of the admixed solution of 

 bichromate of potash. 



Usually, in blood of healthy persons, examined as I have 

 described, in about an hour from the time the drop of blood is 

 placed on the slide, a few of the corpuscles that are least deeply 

 colored appear to have become somewhat granular in their in- 

 terior. Focussing shows that this is not the optical illusion 

 alluded to in the case of knobbiness of the surface. 



