1862.] OF THE BLOOD OF VERTEBRATES. 93 
teresting it is, among the first anatomical fruits of Mr. Lister’s very 
important labours in the improvement of the microscope, and withal 
so accurate that it ought at once and for ever to have dispelled any 
further belief in this imaginary nucleus of the blood-dise of Man. 
Yet, after all, it does not appear that their observations were pushed 
far enough to verify the remarkable exactness of Hewson’s descrip- 
tion regarding the oviparous Vertebrata, but ouly to show its inac- 
curacy when applied to Mammalia. And so here we were left to the 
distraction of half-truths, that fruitful source of error, very pre- 
cise and conscientious in themselves, but still so confounding two 
things fundamentally different as to obscure the whole truth. ‘This, 
indeed, as in so many other cases, lay between both parties; for the 
descriptions of Hewson and of Hodgkin and Lister are quite accurate 
and real, when confined, as they ought always to be, to the class of 
animal on the blood of which those excellent observers were severally 
engaged. 
Lastly, in 1842 and 1845 Mr. Wharton Jones in England, and 
M. Donné on the Continent, fully coincided with me as to the dif- 
ference in question between the Mammalia and the lower Vertebrata ; 
and this essential fact as to the “‘ vexed question of a nucleus”? was 
then established evermore, though in 1841 Dr. Rees and Mr. Lane 
were still maintaining that there really is a nucleus in the blood-dise 
of Man. But their supposed nucleus seems to be identical with 
what I have always depicted and described as the membranous base 
or frame of the corpuscle, and similar to the part figured by Home 
and Bauer, but a very different thing from a nucleus. 
Now, if we wash the red corpuscles of Mammalia in water, using 
a tall narrow jar or even a test-tube, allowing them to subside, de- 
canting the supernatant liquid, and adding fresh portions of it until 
all the colouring-matter and viscid part be removed, there will be a 
whitish precipitate, consisting mostly of pale, thin, nearly trans- 
parent, flattened circular discs. These are the membranous bases 
or frames of the corpuscles-—corresponding to the globuline of some 
authors—quite insoluble in water, and so faint as not to be easily 
seen until their opacity has been increased by some such reagent as 
corrosive sublimate, which makes them very distinct. In short, this 
washed corpuscle is its colourless tegumentary frame, which, thus 
treated, is finer and smaller than (that is to say, about two-thirds 
the diameter of) the fresh unwashed corpuscle, thinner and of larger 
comparative diameter than the nucleus of the blood-dise of oviparous 
Vertebrata, and approaching in size to, but wanting the globular form 
of, the objects represented in the beautiful drawings by Bauer :— 
Fig. 1. Outlines of the human corpuscle, the first and second as 
seen flat and on edge ; and the third showing the thin, delicate, faint 
and colourless membranous frame or base of the same, and entirely 
devoid of a nucleus, after three days washing in water. At fig. 12 
is seen, first, a sketch of a regular corpuscle of a bird, and next, the 
same corpuscle made round, and clearly showing its nucleus after 
similar washing in water. This washed corpuscle is represented 
rather larger than it should be. 
