STRUCTURAL RELATIONS OF RED BLOOD-CORPUSCLES. 379 



definable, but they appear very irregularly bounded and provided 

 on the surface with all sorts of elevations and depressions {a, b). 

 Nothing is seen besides the perfectly colourless mass which 

 refracts light strongly. 



It is very seldom that the disk-form is found represented 

 among these homogeneous colourless blood-corpuscles (c). It 

 shows then, as before the decoloration, a shallow depression in 

 the centre and the effects of light and shade dependent on it. 



More frequently mulberry shapes are met with, which appear 

 furnished on the surface of the more or less globular mass with 

 processes, sometimes coarse and scanty, at other times finer and 

 more numerous {d, e). Each one of these processes is as homo- 

 geneous and highly refractive as the bright colourless substance 

 from which it arises. We have here therefore the same colovrless 

 mulberry and horse-chestnut shapes which I had previously ob- 

 tained from the red blood-corpuscles of the cat by treating 

 them with aqueous humour {Archiv fur Path. Anat. vol. xxxix, 

 plate ix, figs. 1 — 5). 



Amongst the blood-corpuscles belonging to this group I must 

 also mention those which possess on their surface a peculiar 

 striation. In blood-corpuscles of very different forms (as is 

 indicated in the drawings fig. 1, /, g, h, i, k), there is seen on 

 the shining surface a series of parallel transverse strise {/) ; in 

 other cases the blood-corpuscles appear notched like a shell with 

 fine indentations, running in curved lines, between which equally 

 regular elevations occur {g, h, i). Sometimes these are espe- 

 cially fine and converge from the two sides to the median line, or 

 they form a radiate figure which proceeds from the centre into 

 the colourless homogeneous substance of the blood-corpuscle {k). 

 Sometimes I have also observed the following form. The 

 blood-corpuscle had almost assumed the shape of a fungus, and 

 become divided into two parts, still connected, although separated 

 from each other to a certain degree. The chief mass formed a 

 concavo-convex disk, presenting the homogeneous shining appear- 

 ance described above. The part joined on to the concave surface 

 consisted of a number of filaments, also of bright aspect, which 

 at one end were sunk into the disk and at the other end blended 

 with one another {b). 



I did not wish to omit drawing attention to the above forms, 

 as I do not consider them accidental and unimportant, but think 

 I can prove that they are intimately connected with the internal 

 organisation of the red blood-corpuscles about to be described, 

 and must be considered as derived from these. 



2. A second group of blood-corjmscles, which is very largely 

 represented, is characterised by the fact that two sicbstances can 

 be distinguished in them, viz. a homogeneous shining cortical layer 



