STEUCTUEE OF COLORED BLOOD-COEPUSCLES. 95 



certain point, paling occurred in an increasing degree, and a 

 morphological structure became visible at the same time that the 

 manifestations of life (contraction and amoeboid movement) con- 

 tinued. From this we certainly may infer that the re-agent 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 re-agents in other 

 living matter, the inference that they were preexisting, and not 

 artificially produced by the re-agent, 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 questions 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) of the body. Broadly 

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

 puscles is the presence of haemoglobin, 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 j nevertheless, the outer portion, essentially like the inner 

 substance forming the net- work, may be considered to 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 j 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, in 1873, 

 Heitzmann demonstrated the existence of a net- work in amcebae, 

 blood-corpuscles of astacus and of triton, human colorless blood- 

 corpuscles and colostrum corpuscles ; and, from direct observa- 

 tion of the changes in the reticulum during the contraction of 

 the living body, announced that the substance constituting the 

 net-work is itself the living matter or bioplasson i. e., "the 



