Blood-eorpuscles of A. tridactylum, &c. By Dr, Schmidt. 59 
menon mentioned, unless the supposed pores represent conical 
tubes radiating from the centre toward the periphery. But as 
these have never been seen, of whatever shape they might be, the 
hypothesis has no foundation of observed facts to rest upon. 
Nevertheless, it has been received as the true theory by a number 
of histologists. Even Strieker has adopted this theory with a 
slight modification. 
Hensen,"^ in observing the above-mentioned phenomenon, ex- 
plained it as caused by the protoplasm of the coloured blood-cor- 
puscles, collected around the nucleus and upon the inner surface of 
the cell-membrane (which he presupposed to exist), and connected by 
delicate filaments, radiating from the nucleus to the membrane ; the 
interspaces left between the filaments contain the coloured liquid 
contents of the cell. 
A similar theory, regarding the structure of the coloured blood- 
corpuscles of the Frog, has been advanced quite recently by Koll- 
mann.t He also presumes the existence of a stroma, formed by a 
dense network of delicate filaments, extending from the nucleus to 
the transparent, elastic, enveloping membrane ; the interspaces left 
between the filaments he supposes to contain the haemoglobin. 
The characteristic form of the blood-corpuscles he supposes to be 
only possible by a certain degree of tension in the albuminous 
filaments of the stroma. An excessive contraction of the filaments 
is counterbalanced by the haemoglobin contained in the interspaces. 
The coloured blood-corpuscles of the Mammalia also, have, accord- 
ing to his view, such a stroma. 
Laptschinsky,t judging from the effect of different reagents 
upon the coloured blood-corpuscles of Tritons and Man, supposes 
them also to consist of two different substances. The one of these, 
designated by him as the “ rest of the blood-corpuscle,” is soft and 
elastic, and assuming mostly a round form, possesses in general all 
the properties of the so-called “stroma” of these bodies. The 
second substance becomes under the microscope only visible when, 
by the effect of different reagents, it is made to swell or preci- 
pitate. 
Still other hypotheses concerning the structure of the coloured 
blood-corpuscles and the phenomena which they manifest, have been 
advanced ; but as this article is not intended to present the history 
of these bodies, I shall forbear mentioning them. 
In the course of the numerous investigations into the nature of 
the colom’ed hlood-corpuscles, especially of the larger ones, con- 
taining a nucleus, they have, of course, been treated in various 
ways — mechanically, chemically, and physically; and there re- 
* Strieker, ‘ Handbucli der Lehre von den Geweben,’ j). 205. 
t Virchow and Hirscli, ‘ Jaliresberiebt, &c.,’ flir das Jalir 1874, band i. p. 40. 
j Log. cit., p. 40. 
