383 PROFESSOR ARTHUR BOETTCHER. 



represented in fig. 4 it has been possible to demonstrate the 

 attributes of a cell to an extent hitherto unlooked for. 



After I had, by means of the advantages possessed by the 

 above-described method, managed to distinguish the nucleus of 

 the red blood-corpuscles from the surrounding protoplasm, it was 

 natural that those forms, in which within the homogeneous cortex 

 only a granular substance stained red by carmine is seen, should 

 receive another interpretation. It is evident that the central mass 

 of the blood-corpuscles represented in fig. 2, a — g, cannot be the 

 nucleus, but only the protoplasm. It may be taken for granted 

 that the former cannot be detected in them only, because circum- 

 stances are not favorable for seeing it. Probably the mass of 

 the granular substance simply prevents its being seen. The same 

 may be asserted of the forms represented in figs. 3 and 5 ; but 

 with regard to these I have something to add which appears 

 important in order to understand them rightly. 



The processes of the protoplasm, as already mentioned, may 

 be considerably developed and extended to some length (fig. 3). 

 In other cases, however, they are short and of capillary fineness 

 (fig. 5, a, b, c). The central granular ball then appears as if 

 invested with fine bristles on all sides ; this occurs both in the 

 more compact forms {a) and also in the thin elongated spindles 

 (c). It also happens sometimes that the processes are conical, 

 which causes the protoplasmic mass inside the homogeneous cor- 

 tex to assume accurately the aspect of a mulberry -shaped blood- 

 corpuscle {d). It also appears that its surface is not always 

 similar on all sides, but one side may be beset with papilla-like 

 elevations, whilst the other appears simply granular ((?). 



After all, it may be considered certain that the protoplasm of 

 the red blood-corpuscles, when these are introduced into a con- 

 centrated alcoholic solution of corrosive sublimate, sometimes 

 becomes rigid with extended processes, and at other times appears 

 in a contracted condition, as in fig. 2. If, now, in such blood- 

 corpuscles a transverse striaiiott of the protoplasm can be fre- 

 quently recognised (fig. 2, c) this must be referred, I believe, to 

 imperfectly developed processes, which, running in a particular 

 direction, cannot be recognised as such in a certain position of 

 the blood-corpuscles, but give to the granular part a striped 

 appearance. The drawings a, d, c, in fig. 5 seem to me to justify 

 this conclusion, for with inferior lenses I see in these blood- 

 corpuscles nothing more than a striation of the protoplasm. 



The relation of the protoplasmic portion to the homogeneons cortical 

 layer is also deserving of especial consideration. In reference to 

 this, it is necessary to point out, in the first place, that in a large 

 proportion of the blood-corpuscles the nature of the sxirface is 



