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MR. T. WHARTON JONES ON THE BLOOD-CORPUSCLE. 
To complete the history of the blood-corpuscle, it remains to inquire into the first 
formation of the granule blood-cell on the one hand, and into the ultimate fate of the 
nucleated blood-cell of the Invertebrata, and of the oviparous Vertebrata, and of the 
free celleeform nucleus of Man and the Mammifera on the other ; and also to collate 
the views given of the development of the blood-corpuscle with the theory of cell 
development in general. 
In executing this task I shall have an opportunity of considering several questions 
which have suggested themselves in the present series of papers, but which it would 
have been premature to have entered upon. 
Professor Rudolph Wagner, viz. that the corpuscles of the circulating fluid of the Invertebrata are not any 
of them analogous to the red blood-corpuscles of the Vertebrata, but are all of them analogous to the corpus- 
cles of the lymph, or chyle merely, and that therefore the circulating fluid of the Invertebrata is “ mere chyle, 
not proper blood,” proper blood being, as he defines it, “ a red coloured fluid containing characteristic corpus- 
cles.” 
This view appears to me to be distinction without essential difference, and to have arisen, — 1st, from an im- 
perfect acquaintance with the corpuscles of the lymph of the Vertebrata, and their relationship to those of the 
blood of the same division of animals on the one hand, and with the corpuscles of the circulating fluid of the 
Invertebrata on the other ; 2ndly, from laying too much weight on the presence or absence of colour as a di- 
stinctive character; thus making no distinction between the “red corpuscle” of the blood of the Mammifera, 
and the “ red corpuscle ”of the blood of the oviparous Vertebrata in consequence of their similarity in colour, 
though there is between them an essential organic difference; whilst between the “red corpuscle” of the 
blood of the oviparous Vertebrata and the nucleated cell of the circulating fluid of the Invertebrata, in conse- 
quence of a supposed total absence of colour in the latter, a decided distinction is made, though there is, in fact, 
between them no essential organic difference. 
Waiving, however, the organic difference between the “ red corpuscle” of the Mammifera and the “red 
corpuscle” of the oviparous Vertebrata, and the organic resemblance between the “red corpuscle” of the ovi- 
parous Vertebrata, and the little or not at all coloured nucleated cell of the circulating fluid of the Inverte- 
brata, I would observe in regard to the presence or absence of colour, that nothing bearing on the question can 
be inferred from it, even in a physiological point of view, seeing that the nature and use of the red colouring 
matter of the “ red blood- corpuscles” are as yet too little known. 
The colour of “ red blood- corpuscles ” is now acknowledged not to be owing to the iron entering into their 
composition, and therefore it is not, as has been supposed, a manifestation of the existence of any endowment 
which may be possessed by the “red corpuscles” by virtue of the iron which they contain. But even if this had 
been so, the fact above mentioned, of the presence of iron in the uncoloured or but little coloured corpuscles of 
the blood of the Crab, renders it extremely probable that what endowment soever may be possessed by the “ red 
corpuscles” of the Vertebrata by virtue of the iron which they contain, may be equally possessed by the corpus- 
cles of the blood of the Crab. 
Professor Wagner adduces arguments of another kind in corroboration of his view, that the circulating fluid 
of the Invertebrata is “ mere chyle, not proper blood ;” but which it is scarcely necessary to notice after what 
I have just said, especially as their force, so far as it is evident, appears to bear more against than in favour of 
his view. 
