168 Or THE BLOOD. 



the White and the Red corpuscle are thus described by Mr. Paget 1 as they are 

 seen in Human blood. " The white corpuscle, at first tuberculated, containing 

 many granules, and darkly shaded (Fig. 16, A), becomes smoother, paler, less 

 granular, and more dimly shaded or nebulous (B). In these stages the cell- 

 wall may be easily raised from its contents by the contact and penetration of 

 acetic acid, or by the longer action of water (c) ; and, according to the stage of 



Development of human lymph and chyle corpuscles into red corpuscles of Blood. A. A lymph, or -white 

 blood-corpuscle. B. The same, in process of conversion into a red corpuscle, c. A lymph-corpuscle, with the 

 cell-wall raised up round it hy the action of water. D. A lymph-corpuscle, from which the granules have 

 almost all disappeared. E. A lymph-corpuscle, acquiring color ; a single granule, like a nucleus, remains. F. 

 A red corpuscle, fully developed. 



development, so are the various appearances which the contents of the cell thus 

 acted on present. In the regular progress of development, it becomes at length 

 impossible to raise the cell-wall from its contents (D). Then the corpuscles 

 acquire a pale tinge of blood-color; and this always coincides with the softening 

 of the shadows which before made them look nebulous, and with the final 

 vanishing of all the granules, with the exception sometimes of one, which re- 

 mains some time longer like a shining particle in the corpuscle, and has proba- 

 bly been often mistaken for a nucleus (E). The blood-color now deepens, and 

 at the same rate the corpuscles become smooth and uniform ; biconcave, having 

 previously changed the nearly spherical form for a lenticular or flattened one ; 

 smaller, apparently by condensation of their substance, for at the same time 

 they become less amenable to the influence of water ; more liable to corrugation 

 and to collect in clusters; and heavier, so that the smallest and fullest-colored 

 corpuscles always lie deepest in the field (F). Thus the most developed state 

 of the Mammalian red corpuscles appears to be that in which they are full- 

 colored, circular, biconcave, small, uniform, and heavy; this is also the state in 

 which they appear to live the longer and most active portion of their lives. " 

 Thus, then, the lymph and chyle seem to be continually supplying, not merely 

 the pabulum for organization derived from the food, but an important kind of 

 organized bodies, the existence of which in the blood is essential to the well- 

 being of the entire system ; and this view is confirmed by the fact, that the 

 fluid, not only of the thoracic duct, but also of the larger lymphatics, frequently 

 possesses a roseate hue (which sometimes makes itself apparent in the horse 

 even through the walls of the thoracic duct), and that this is attributable to the 

 presence in it of corpuscles which seem to be in process of transformation into 

 the Red corpuscles of the blood, being smaller, paler, and less perfect in shape. 3 



1 "Manual of Physiology," pp. 65-6, Am. Ed. 



2 See Mr. Gulliver's observations, in his edition of '-Hewson's Works," p. 276, and in 

 the Translation of "Gerber's General Anatomy," p. 93. 



