68 MR. T. WHARTON JONES ON THE BLOOD-CORPUSCLE CONSIDERED IN 
pus-corpuscle, a particular view has been founded as to the first formation of the 
nucleus, and indeed as to cell development generally. This subject I hope to consider 
on another occasion. 
31. To return. I have observed that when the blood was treated with water first, 
so as to distend fully the cells in question, and then the acetic acid added in a very 
dilute state, never more than a single large cellseform nucleus came into view; 
whereas if the acid was added a little less diluted, and before the distending action 
of the water had been allowed to have its full effect on the cell, very generally an 
appearance of two or more small cellseform nuclei came into view. Though these 
nuclei have sometimes appeared as if detached from each other, they have been usually 
in contact, and I have been able to trace the contour of the original single cellseform 
nucleus from the one small body to the other. 
32. By the action of water alone I have, indeed, sometimes seen, in those cells in 
which the nucleus is already visible through the finely granulous contents, an appear- 
ance as if the nucleus were subdivided into smaller, but very generally this has not 
been the case. 
33. The distortion of shape, produced by external agencies, which I have now 
described as giving a false idea of the real structure of the cellseform nucleus of the 
granule-cell of the Frog, has its analogue in the now well-known distortion which 
the primitive tubules of nervous substance so readily undergo. 
34. Nucleated Blood-cells — Uncoloured stage. — In the blood of the Frog, besides 
the granule-cells just described, there are seen uncoloured but distinct and well- 
defined corpuscles, round or oval, finely granulated, and refracting the light to a 
certain degree, and about g-^oth °f an inch in diameter. 
35. These corpuscles are apt to be confounded with the granule-cells, and appear 
to have been sometimes taken for free nuclei. They are nuclei but not free*, being 
surrounded by a cell-wall, which, without a good microscope and good light, is readily 
overlooked on account of its great paleness. This very pale cell, with distinct nucleus, 
which is the nucleated blood-cell in the uncoloured stage, may be circular (fig. 4.), 
or oval (fig. 5.), and of a size approaching that of the red corpuscle, or nucleated cell 
in the coloured stage. 
36. Sometimes the pale cell-wall so closely embraces the nucleus as not to be 
distinguishable at all until distended and brought out by the addition of water, when 
it appears as represented in fig. 3. 
3/. This nucleated blood-cell in the uncoloured stage of the Frog is very similar 
to that of the Skate, the principal or indeed only difference being that its nucleus has 
become solid-looking and condensed, so that it has little of the cellseform appearance 
which the nucleus of the corresponding cell in the Skate presents. 
38. Nucleated Blood-cell — Coloured stage. — This is the well-known red oval cor- 
puscle of the blood of the Frog (fig. 6.). It is the counterpart of the red oval cor- 
* There may sometimes be seen free nuclei (par. 101.), Note. 
