24 On the Cellular Structure 



nucleus of all nucleated red blood globules, and is free from 

 haemato-globulin, while the remaining portion contains the entire 

 mass of the latter. The last-mentioned part Briicke considers as 

 lying in the interspaces of the porous mass, filling them completely, 

 but at the same time forming a continuous whole with the non- 

 pigmented portion. The colourless porous substance he calls 

 Oilcoid, all the remainder he names Zooid ; and considers that, by 

 the partial or complete withdrawal of the Zooid from the Oikoid, 

 the occurrence of the above-mentioned appearances is explained. 

 Strieker himself behoves in the Oikoid of Briicke, but calls the 

 remainder of the corpuscle its body (der Lieb)." 



Eecapitulating now the facts which I have detailed, miHtating 

 against the views of Flint, Beale, and Ch. Eobin, who hold that the 

 red blood corpuscles of mammals are homogeneous drops of a jelly- 

 like substance, we find first, that when human blood is diluted with 

 pure water, the bi-concave disks in general gradually assume a 

 bi-conves and finally a globular form, their coloured portion being 

 entirely dissolved, sometimes in the course of a few minutes, while 

 the transparent colourless constituent which retains the spherical 

 shape is completely insoluble in water, even during the prolonged 

 maceration of over thirty days ; and second, that when a mass of 

 desiccated corpuscles, such as occurs in a dried blood-clot, is washed 

 with pure water, so as to remove all the hsemato-crystallin, the 

 outlines of the compressed red blood disks may be readily de- 

 tected on examination with a sufficiently high power ; further, that 

 in the red globules of the Menobranchus, which may be supposed 

 to bear a more or less close analogy in their constitution to those of 

 mammals, it is possible to analyze the corpuscle by separating the 

 coloured cell contents from the colourless cell wall, either by punc- 

 ture of the membrane, by crystallization of its enclosed fluid, or by 

 pressure upon the corpuscle, forcing out its contents apparently 

 through the pores of the membranous capsule in the same manner 

 that quicksilver is strained by pressure through the sides of a 

 buckskin bag. 



In opposition to the theories of Hensen, Strieker, and Briicke, 

 who consider the red blood corpuscles are made up of a colourless 

 porous substance called Oikoid, and a coloured more fluid ingredient 

 denominated Zooid, may be enumerated the following circumstances : 

 — First, if, on the one hand, we consider that a porous substance 

 of the definite bi-concave form, analogous to a disk of compressed 

 sponge, exists, it seems impossible to account for this stroma 

 assuming a globular shape when acted upon by water, since the 

 full diameter of the sphere, when formed, is occupied by the least 

 amount of distended matter, while the dimension, in which lay the 

 greatest bulk of stroma previous to the addition of water, is actually 

 diminished ; on the other hand, any hypothesis that the porous 



