On some Constituents of the Cell. 
BY 
JAMES ELLIS HUMPHREY, S.D., 
Lecturer in Botany, Johns Hopkins University , Baltimore , U.S.A. 
With Plate XX. 
YEAR and a half ago the writer published (’94) a brief 
preliminary account of the results of studies on the 
cell, carried on in the Botanical Institute at Bonn, under the 
inspiring guidance of Professor Strasburger. Since then these 
studies have been continued and extended in America, and 
meanwhile several papers bearing on the same questions have 
appeared. It seems, therefore, now worth while to examine 
the views then brought forward in the light of the latest and 
fullest evidence from all sources. Various details and general 
considerations which are stated in my earlier paper will hardly 
require to be repeated here. 
The question as to the nature of the bodies long known as 
nucleoli has been made prominent by a paper of Zimmermann 
(’93) on their behaviour during karyokinesis. These bodies, 
while they readily take up very many stains, and are perhaps 
the most conspicuous features in preparations of the resting 
nucleus, are not so stained by all media as to be readily 
distinguishable from all other constituents of the cell. But 
until our knowledge of the higher organic compounds is 
[Annals of Botany, Vol. IX. No. XXXVI. December, 1895.] 
