Vol. 6, 1920 
ZOOLOGY: D. H. TENNENT 
217 
2 Earl of Berkeley, and Hartley, K. G. J., London, Proc. R. Soc. (A), 92, 1916 (477). 
3 Loeb, J., /. Gen. Physiol, I, 1918-19 (559). 
4 Loeb, J., Ihid., I, 1918-19 (483). 
5 Loeb, J., Ibid., 2, 1919-20 (87, 273). 
6 The influence of electrolytes on the osmotic pressure of gelatin is not due to differ- 
ences in the degree of electrolytic dissociation of the gelatin salts, since, e.g. Na gela- 
tinate and Ca gelatinate of the same concentration of gelatin and hydrogen ions have 
practically the same conductivity.^ 
7 Loeb, J., /. Gen. Physiol, 2, 1919-20 (173, 255); these Proceedings, 5, 1919 (440). 
8 Girard, P., Paris, C. R. Acad. Sci., 146, 1908 (927); !48, 1909 (1047, 1186); 150, 
1910 (1446); 153, 1911 (401); La pression osmotique et le mechanisme de I'osmose, 
Publications de la Societe de Chimie-physique, Paris, 1^912; Bernstein, J., Electrohiologie, 
1912; Bartell, F. K., /. Amer. Chem. Soc, 36, 1914 (646); Bartell, F. E., and Hocker, 
C. D., Ibid., 38, 1916 (1029, 1036); Freundlich, H., Kolloid-Zs., 18, 1916 (11). 
9 Hamburger, T., Zs. physik. Chem., 92, 1917 (385); {Ann. Physik, Beiblatter, 42, 
1918 (77)). 
10 Perrin, J., /. Chim. Physique, 2, 1904 (601); 3, 1905 (50); Notice sur les titres et 
ravaux scientifiques de M. Jean Perrin, Paris, 1918. 
EVIDENCE ON THE NATURE OF NUCLEAR ACTIVITY 
By David H. Tejnnent 
Bryn Mawr C01.1.EGE AND Department oe Marine Biology, Carnegie Institution 
OF Washington 
Communicated by A. G. Mayor, February 10, 1920 
Binuclearity hypotheses, founded in part on Richard Hertwig's chro- 
midial hypothesis, have influenced interpretations of extra-nuclear bodies 
in the cytoplasm profoundly. The obvious dual capacity of the metazoan 
nucleus, exhibited in kinesis and interkinesis, i.e., in generative (propa- 
gatory), and somatic phases, has been made to lend itself to analogy with 
a true binucleate condition and to an assumption that the nucleus contains 
two kinds of chromatin. Of these one is supposed to be propagatory 
(idiochromatin), in evidence at the time of cell division, the other trophic 
(trophochromatin, somatochromatin) , formed by the idiochromatin, but 
resident in the cytoplasm. This phase of the binuclearity idea is quite 
independent of that to which support is given by the demonstration of 
dimorphism in chromosomal groups during oogenesis and spermatogenesis. 
The somatic phase of the nucleus covers the period during which it 
may be assumed that the nuclear enzymes have passed from the nucleus 
to the cytoplasm, and the cytoplasm has become the seat of synthetic 
activities. The nucleus at this time is in a ''resting" condition; it seems 
comparatively empty, is acidophile, and basophilic granules may be found 
in the cytoplasm. 
What is the nature of these basophilic bodies? Are they of direct or 
indirect nuclear origin? 
The accounts of the extrusion of chromatin from the nucleus are numer- 
rtis. Under the influence of the binuclearity hypothesis supposed particles 
