APPEARANCES OF THE RED BLOOD-CORPUSCLES. 157 
In 1863 Klebs,! observing the blood of dead animals warmed 
to bodily temperature, observed points projecting from the 
surface of the red corpuscles, the larger of which often divided 
into two parts, the corpuscles themselves becoming distorted. 
The description is very meagre, and the appearances may be 
little more than the prickly, or as it has been termed the hedge- 
hog form of the corpuscles. 
In the same year Rindfleisch? published some experimental 
observations on the blood. He found that in extravasated 
blood of the frog the red corpuscles became round, and a portion 
of their’contents, as he describes it, protruded, forming fila- 
mentous processes, or a rosary of red-coloured droplets, on the 
surface of the corpuscles; these he considers are protruded 
through pores or other openings in the cell-wall, the droplets 
of which they consist being held together by a viscid substance. 
He further states that these appearances may also be produced 
by a concentrated solution of urea. 
The first mention of the effect of urea on the red blood- 
corpuscles which I have seen is by Dr. T. L. Huenefeld, in a 
work published in 1840,? in which he describes the action of 
a great number of reagents, and states that a solution of pure urea 
does not seem to have much effect on the red blood-corpuscles of 
man or ‘the pig, beyond that it dissolves out the colouring matter 
very quickly, leaving only portions of the hull and the nucleus 
visible. 
In 1864, Dr. Beale* describes and figures the changes of 
form in the red blood-corpuscles of man from heat, the pro- 
cesses and appearances presented, though more varied than those 
described above, are obviously of the same character. The 
paper was written in support of the author’s theory of formed 
and living matter. In the same year Preyer® describes the 
appearances in extravasated blood of the frog on the warm stage. 
Long processes are formed, and globules which become de- 
tached and sometimes reunite with the parent corpuscle. He 
remarks that the action of urea will produce similar appearances, 
which only differ slightly in colour, and makes the observation, 
that im the blood of frogs at breeding time, nuclei evidently 
dividing are found; these he figures. The processes above 
described he also finds in the blood of frogs on the warm stage 
without any reagent. 
1 *Centralblatt. f. ci. Medicinisch Wissen.,’ Bd. i, 1863, s. 851. 
2 ¢ Hxperimentalen Studien iiber des Blutes,’ Leipsig, 1868. 
3 ‘Der Chemismus in der thierischen Organisation,’ Leipsig, 1840. 
4 This Journal, N. $., vol. xii, p. 32, 1865. 
5 “Ueber Amcehoide Blut-Korperchen,” Virch. Archiv,’ Bd. xxx, 
. 438, 1865. 4 
Dw 
