270 A. B. MACALLUM. 
pound, chromatin, not only in the hematoblasts, but in all the 
cells of the body. The consequently lessened proliferation of 
cell and tissue would explain the hypoplasia of the imper- 
fectly developed vascular system observed by Virchow! in 
chlorotic human subjects. 
Accepting this explanation of the nature of chlorosis, one may 
infer that this condition is not limited to animal organisms 
in which hemoglobin is found, although its occurrence in 
others may be difficult to detect because of the total absence 
of this pigment. From this point of view animal chlorosis 
is fundamentally similar to the chlorosis of the vegetable 
kingdom. 
The oxygen-carrying property of hemoglobin and of hema- 
tin is generally attributed to the iron present in these, because 
when hematin is deprived of its iron, the resulting compound, 
whether hematoporphyrin or bilirubin, manifests no affinity 
for oxygen. The proof may not be quite conclusive, for we 
cannot be certain that either compound represents the un- 
changed remainder of the hzmatin less its iron, but assuming 
that it is correct, it follows, as I have pointed out in my pre- 
vious communication, that the antecedent of hemoglobin, 
chromatin, has the capacity of absorbing and retaining oxygen, 
and that one may attribute the processes grouped under the 
term “ vital,” to an alternation of the conditions of oxidation 
and reduction in the iron-holding nuclear constituent. This 
hypothesis, reasonable as it now appears to me to be, I do 
not regard as free from difficulties, since in vegetable cells the 
two processes of respiration and assimilation, involving two 
activities of different natures, so far as the oxygen is concerned, 
appear to postulate the existence of two different iron com- 
pounds in the same nucleus.” There are no facts to indicate 
1 “ Ueber die Chlorose und die damit zusammenhingenden Anomalien im 
Gefassapparate, insbesondere tiber Endocarditis puerperalis,”’ ‘ Vortrag.,’ 
Berlin, 1872. 
? On the relations of the vegetable nucleus to the processes of assimilation, 
see Strasburger, ‘Ueber Kern- und Zelltheilung im Pflanzenreiche,’ 1888, 
pp. 194—204. 
