The Struct urc of Colored Blood- Corpuscles. 309 



From this, we certainly may infer that the reagent has not altered, 

 at all events not seriously impaired, the living matter ; and when 

 we find that the structural arrangements thus revealed are the 

 same as those demonstrable without reagents in other living mat- 

 ter, the inference that they were pre-existing and not artificially 

 produced by the reagent becomes a certainty. 



The knowledge of the structure of colored blood-corpuscles 

 will not enable us to solve all the problems regarding their 

 nature ; but some epiestions are answered pretty conclusively by 

 my investigation. 



The colored blood-corpuscle is not a cell in any proper sense 

 of that word, but, like the colorless corpuscle, is an unattached 

 portion of the living matter (bioplasson 1 ) of the body. Broadly 

 speaking, the essential difference 2 between the two kinds of cor- 

 puscles is the presence of hannoglobin, using this term to desig- 

 nate the substance or substances — no doubt chemically very 

 complicated — constituting the coloring matter under all the 

 varying physiological circumstances. 



In size, human colored blood-corpuscles vary so much, that 

 claims to be able to distinguish them by their size from certain 

 other mammalian colored blood-corpuscles are inadmissible. 



The colored blood-corpuscle has no separate investing mem- 

 brane ; nevertheless, the outer portion, essentially like the inner 

 substance forming the net-work, may be considered tcr be differ- 

 entiated from the latter, especially at the periphery of the disk, 

 where it constitutes an encircling band of uniform thickness, or 

 occasionally of a wreath-of -beads appearance. In the colored 

 blood-corpuscles of the lower classes of vertebrate animals there 

 is usually a nucleus to be seen, which is not the case as a rule in 

 those of man and other mammalians ; but there is in the interior 

 of these an accumulation of matter occasionally met with, which 

 may be interpreted as a nucleus. 



In the communication to the Vienna Academy, cited in Part I, 



(1) I use the word bioplasson as synonymous with li living matter" in preference to the 

 better known word " protoplasm," because the former is etymologically more correct, and 

 also because the latter has been used with other meanings attached to it than the one alone 

 intended here, viz., living matter. 



(2) The differences in the possession of nuclei I shall discuss on another occasion. 



