The Possible Function of the Nucleolus 
in Heredity. 
BY 
H. H. DIXON, Sc.D., 
Trinity College , Dublin. 
TRASBURGER, I believe, was the first to suggest that 
O the nucleus is the bearer of the hereditary qualities of 
the organism 1 . Subsequent observation and deduction have 
certainly gone far to establish this theory, and now the 
majority of biologists believe, it may be with some mental 
reservation, that the hereditary substance is transmitted in 
the nucleus, or more precisely in the chromatin-thread of the 
nucleus 2 . 
The view advanced here, and urged merely as a tentative 
suggestion, is a slight extension of the generally accepted 
theory. According to it the hereditary substance or germ- 
plasm is to be regarded as completely contained within the 
chromatin-elements (chromosomes) during nuclear division, 
as is at present generally held ; but during the resting-stage 
of the nucleus, it is suggested as probable that the hereditary 
1 E. B. Wilson (The Cell in Development and Inheritance, p. 5) says that 
Haeckel expressed this view as early as 1866, but that O. Hertwig, Strasburger, 
Kolliker, and Weismann almost simultaneously identified the nucleus as the 
vehicle of inheritance in 1884-5. 
3 Wilson, 1 . c., p. 257. 
[Annals of Botany, Vol. XIII. No. L. June, 1899.] 
T 
