43 
NeruMANN’s THEORY of the DEVELOPMENT of 
Brioop-corPusces.! 
Tuer development of the blood is certainly one of the 
least understood physiological processes, and especially is this 
true of its cellular elements. The most diverse opinions 
have been held respecting the origin of the white cells, their 
transformation into red, and the ultimate fate of the latter. 
In the first place, the embryonal development of blood was 
regarded as the key to the mystery ; and since in the embryo 
the development of red corpuscles takes place from the white 
or lymph cells, through the intermediate form of a coloured 
nucleated cell, a similar process was assumed to take place in 
the adult body. Since, however, the intermediate form—a 
coloured nucleated cell—could not be found in the blood of 
the adult organism, it was supposed by one party (Kolliker) 
either that these forms might exist in some part of the body not 
examined, or else that the absence of transitional forms was 
to be explained by the rapidity of the transformation. Another 
party gave up the theory of transformation of white into red 
corpuscles, and sought another mode of origin for the latter. 
Thus, according to Wharton Jones and Bennett it was the 
nuclei of the lymph cells which were transformed into the red 
corpuscles. According to H. Miiller, the latter arose from a 
fusion of nucleus and cellin the smaller lymph-cells. Gerlach, 
Funke and others believed in an endogenous formation of 
red corpuscles in larger cells, while Zimmermann had recourse 
to some entirely different elements of the blood itself. 
Since, however, none of the latter views could be satisfac- 
torily established, the tendency has been to fall back upon 
the hypothesis of a formation of red corpuscles out of the 
white corpuscles of the blood itself. There is no greater 
unanimity of opinion respecting the ultimate fate of the red 
corpuscles, though, in spite of the doubts of Kolliker, it, 
seems probable that there is a continual dying off and new 
production of these elements; and it has been thought that 
a greater or less power of resistance to the action of water is 
a sign of the age of particular corpuscles. The origin of the 
white corpuscles has been pretty generally assigned to the 
1 ‘Untersuchungen iiber die Verschiedenen Theorie’n der Entwickelung 
der Blutkérperchen, besonders tiber die neueste, von Neumann.’ Inaugural 
Dissertation ; von Charles W. Hales, M.B., Leipzig, 1870. 
‘Investigations on the Different Theories of the Development of the 
Blood-corpuscles, and especially on the latest, that of Neumann.’ A 
Graduation-Thesis, by C, W. Eales, (Abstract by J. F. Payne, M.B.) 
“ 
