BLOOD OF MAMMALS. 513 



CHAPTEK XXXII. 



CIRCULATING SYSTEM OF MAMMALIA. 



346. Blood of Mammals. The blood in this class is hot and 

 red, with a proportion of organic matters to the water as great as 

 in Birds, and more abounding in blood-discs, which, as a rnle, are 

 of a circular form, and of smaller size than in Ooipara, consisting 

 of viscous hematosine without a cell-wall (vol. i. fig. 8, a, b). 

 Besides the ordinary red discs there occur pale or granulated 

 vesicles, the appearances of which, in the blood of a Perameles 

 examined by me in 1838, 'suggested the idea that such blood- 

 disc was undergoing a spontaneous subdivision into smaller 

 vesicles.' 1 



The existence of a capsule, or rather a difference between the 

 peripheral and central parts, in ordinary mammalian blood-discs, 

 seems to be demonstrated by submitting them to a solution of 

 magenta, when the contents become a faint rose colour, with a 

 more deeply tinted outline, at least in part of their circumference : 

 occasionally a definite part, like a nucleus, is recognisable. 



In the highest class of Vertebrates the several tissues of the 

 body are best defined and, so to speak, most highly finished : 

 the condition of organic matter by and through which the acts 

 of addition and subtraction are performed in relation to the 

 growth, maintenance, and renovation of such tissues is the 

 formified proteine substance, or organite. It would seem that 

 mere fluid would not serve the purpose : the more solid particles, 



1 CLXXIX", p. 474. This idea has received confirmation in various degrees; e.g., by 

 Quekett ('Med. Gazette,' January, 1840), by Martin Barry (' Philos. Trans.' 1840, p. 

 595), by Wharton Jones (ib. 1846) ; and more recently by Dr. Roberts, of Manchester, 

 in his instructive researches, aided by the effects of a solution of magenta on the blood. 

 ' The pale corpuscles were more strongly tinted than the red ; and their nuclei were dis- 

 played with great clearness, dyed of a magnificent carbuncle-red. A number of the 

 nuclei were seen in the process of division, more or less advanced, and in some cells' 

 (my ' granulate vesicles ') ' the partition had issued in the production of two, three, or 

 four distinct secondary nuclei. There was evidence that these secondary nuclei were 

 set free in the blood, and, by subsequent enlargement and change of form and chemical 

 constitution, developed into red blood-discs.' Proceedings of the Lit. and Phil. Society 

 of Manchester, 1866. 



VOL. III. L L 



