78 MR. T. WHARTON JONES ON THE BLOOD-CORPUSCLE CONSIDERED IN 
of the Mammifera which I am advocating, is just what should be according to it. In 
short, I consider the “ red corpuscle” of the Paco, in its circular form and as yet un- 
coloured state, to be, like the similar corpuscles referred to in par. 86, celleeform 
nuclei but recently set free from the nucleated cell. 
89. 3rd. Correspondence in Structure between the Celleeform Nucleus of the Nucleated 
Cell and the “ Red Corpuscle .” — The celleeform nucleus of the nucleated cell is a simple 
cell or vesicle without nucleus or nucleolus, and as such exactly resembles the “ red 
corpuscle” minus its red coloured contents. Indeed, when by the action of water 
the “ red corpuscle” is deprived of its red coloured contents without being rendered 
indistinct, the resemblance in respect of structure is very striking, as indicated by the 
lumen and transparent circumferential ring — the optical expression of the double 
contour of the wall of the collapsed cell or vesicle. 
90. As already said, “ red corpuscles” may occur uncoloured or with the lumen 
only red, the circumferential ring just referred to remaining transparent and colour- 
less. This indicates that the colouring matter is contained in the interior of the cell 
or vesicle. In its perfect state however the “ red corpuscle” appears red at the circum- 
ference also, owing, apparently, to its wall being impregnated with colouring matter. 
91. The absence of anything like a nucleus in the “red corpuscle” of the fully- 
formed blood of the Mammifera is in correspondence with the absence of anything of 
the kind in the celleeform nucleus of the nucleated cell. The appearance of dots, as 
if of nucleoli, occasionally seen in the latter, I consider to be mere corrugations, similar 
to those which give rise to the mulberry appearance which the red corpuscle is so 
prone to assume. 
92. Before admitting the correspondence in size, form and structure, between the 
celleeform nucleus of the nucleated cell and the “ red corpuscle” of the blood of the 
Mammifera which I have now demonstrated, as evidence in favour of their identity, 
it will be proper to inquire if there be any points of difference between them sufficient 
to constitute evidence to the contrary effect. 
93. Points of Difference between the Celleeform Nucleus of the Nucleated Cell and 
the “ Red Corpuscle .” — 1st. The celleeform nucleus of the nucleated cell refracts the 
light more than the “ red corpuscle.” 2nd. The cellseform nucleus is not affected by 
water or acetic acid like the “ red corpuscles” — the former being by the action of these 
reagents rendered more distinct, the latter rendered indistinct. These circumstances 
indicate a chemical difference between the celleeform nucleus and the “ red cor- 
puscle,” and if a satisfactory explanation of them could not be offered they would 
constitute a powerful argument against my view. But I believe the following ex- 
planation will remove the difficulty. 
94. The objection against the identity of the Celleeform Nucleus and “ Red Corpuscle ” 
which might be founded on the different modes in which they refract light, and are 
affected by Chemical Reagents, explained away.— The differences mentioned are striking 
enough between the cellseform nucleus and the “red corpuscle” in its perfect state; 
but if we take the “red corpuscle” in the stage when, as I have already described, 
