86 



THE BLOOD. 



They seem to be formed of some white substance, 

 variously refracting the light, and containing granules 



which are in some 

 Fig. 26* . 



specimens lew and very 



distinct, in others 

 (though rarely) so nu- 

 merous that the whole 

 corpuscle looks like a 

 mass of granules. 



It is doubtful whe- 

 ther these corpuscles 

 have any true cell-wall. 

 In a few instances an 

 apparent cell - mem- 

 brane can be traced 



around them ; but, much more commonly, even this is 

 not discernible till after the addition of water or dilute 

 acetic acid, which penetrates the corpuscle, and lifts up 

 and distends what looks like a cell- wall, to the interior 

 of which the material, that before appeared to form the 

 whole corpuscle, remains attached as the nucleus of the 

 cell (fig. 26). 



A remarkable property of the white corpuscles, first 

 observed by Mr. Wharton Jones, consists in their capa- 

 bility of assuming different forms, apparently irrespective 

 of any external influence. On watching them while fresh, 

 with a high microscope-power, they can be seen alternately 

 contracting and dilating, at various parts of their cir- 

 cumference, shooting out irregular processes, and again 

 withdrawing them partially or completely, and thus in 

 succession assuming various irregular forms. 



Besides the red and white corpuscles, the microscope 

 reveals numerous minute molecules or granules in the blood, 



* Fig. 26. Eed and white blood-corpuscles, a, "White corpuscle of 

 natural aspect : b, Three white corpuscles acted on by weak acetic acid. 

 c, Red blood-corpuscles. 



