110 The American Naturalist. [February, 
stituents of the nucleus, just as in all metabolic processes there 
is continual interchange, some constituents being elaborated, 
others breaking down into simpler products.” ® We are not to 
forget, however, that these bodies may possibly be fragments 
of still more complex molecules resident in the living karyo- 
plasm of cell nuclei. In any event, the character of these 
fragments, if such they are, must tell us something as to the 
nature of the original molecules, and consequently on the basis 
of the above statements we may reasonably argue the probable 
existence of different, though closely related, chemical varie 
ties of karyoplasm as peculiar to the cell nuclei of individual 
organs and tissues. 
Lilienfeld,” however, while accepting in a general way the 
views already expressed emphasizes the probability that as & 
rule tHere is a constant difference between the nucleus and the 
body of the cell, in that the former in every phase of life con- 
sists mainly of nuclein substances, i. e., nucleo-proteids, nuclein 
and in extreme cases nucleic acid, while the body of the cell 18 
composed mainly of pure proteids and nucleo-albumins with a 
low content of phosphorus. But as there are changing rela- 
tions between these individual bodies, the tone of color 
obtainable by different dyes is obviously more or less variable; 
but as a rule, we may say that the nuclein-containing bodies 
of the nucleus have the strongest affinity for basic dyes 
while the proteids of the cell body naturally seize hold of the 
acid dyes. 
Further, Lilienfeld, who has recently made a thorough 
study of the inner structure of leucocytes and has named the 
characteristic constituent of the nucleus, nucleo-histon, describes 
this body as a nucleo-proteid, a body comparable to a chemi 
salt composed of a proteid base, histon, and a complex acid, 
leukonuclein, which in turn is made up of nucleic ace 
and proteid. So that in this the latest work in this direction that 
I am familiar with, we find results all bearing out the gene? 
statements just submitted.” Again, Lilienfeld has show” 
10 Halliburton ae ; 
1 Verhandlungen der Berliner physiologischen Gesellschaft. Du Bois Reymond* 
Archiv für Physiologie. Jahrgang, 1893, p. 391. 
1? Compare Lilienfeld ‘Zur Chemie de Leucocyten.” Zeitschr. Phyiol. ar 
Band. 18, p. 473. 
