STRUCTURAL RELATIONS OF RED BLOOD-CORPUSCLES. 383 



independent of the form of the protoplasm, i.e. the surface may 

 appear perfectly smooth^ although numerous long protoplasmic 

 processes radiate into the cortical layer (compare tig. 3, fig. 4 b, 

 fig. 5). In other cases, however, the cortical layer appears to 

 follow the processes of the protoplasm, adapting itself to the ele- 

 vations and depressions, and by this means uniformly surrounding 

 the radiating protoplasmic body. This must, I think, be inferred 

 from the different forms, which appear indented in a very peculiar 

 manner (fig. 1). The stripes and swellings on the surface in 

 f, Qi ^) h and k are easily understood if we suppose that pro- 

 cesses situate in the interior of the protoplasm, as we have 

 already seen them in numerous other blood-corpuscles, give rise 

 to the protrusion or indentation of the cortical layer. Still more 

 does the drawing (I) in fig. 1 suggest this interpretation. In 

 this case radiating filaments are actually visible, but they have a 

 homogeneous structure, and are highly refractive like the cortical 

 layer. This peculiarity might, however, be explained by sup- 

 posing that they appear still surrounded by a layer of the cortical 

 substance, after the protoplasmic body has become pushed on to 

 one side and almost isolated. Farther, a companion of fig. 1 e 

 with fig. 5 d renders still more probable the supposition that the 

 protoplasmic processes can exert an influence on the form of the 

 surface. Fig. 1 e represents a decolorised mulberry- shaped 

 blood-corpuscle of a bright homogeneous aspect. In fig. 5 d 

 we find the same mulberry shape in the protoplasm within the 

 homogeneous cortex. Both blood-corpuscles have been exposed 

 to the solution of corrosive sublimate ; but either they possessed 

 on entering the fluid a different relative arrangement of the two 

 parts, or it may have happened that in the one case (fig. 5 d) 

 the action was less momentary and that the protoplasm had time 

 to contract into a sphere beset with protuberances, whereas in 

 the other case the blood-corpuscles (represented in fig. 1 e) im- 

 mediately stiffened in the mulberry forms. In the latter case the 

 general spherical form of the blood-corpuscle and the numerous 

 projections on its surface may have rendered the similarly-shaped 

 central ball of protoplasm very difficult to be seen. It appears 

 to me, therefore, that the possibility at least must be granted 

 that the homogeneous cortical layer is bulged out mechanically 

 by the processes of the protoplasm, and is made to envelope 

 them uniformly. 



If this is not the case, however, in many blood-corpuscles, as 

 we have seen, but the cortical layer remains smooth on the sur- 

 face, although it is traversed by visible processes of the proto- 

 plasm, this may be caused by various circumstances. It is 

 conceivable that in these cases the processes of the protoplasm 

 are either small (fig. 5, a, h, c) and too insignificant to exert 



