Vol. XXV. June, 1913. No. i 



BIOLOGICAL BULLETIN 



THE RELATIVE PERMEABILITY OF THE SURFACE 

 AND INTERIOR PORTIONS OF THE CYTO- 

 PLASM OF ANIMAL AND PLANT CELLS. 1 



(A PRELIMINARY PAPER.) 

 G. L. KITE. 



(From the Department of Pathology and The Otho S. A. Sprague Memorial In- 

 stitute, University of Chicago.) 



The permeability and osmotic properties of cells are explained 

 on the assumption of the presence of surface and vacuolar plas- 

 matic membranes which are of a semi-permeable or partially 

 permeable character. It is generally held that the remainder of 

 the protoplasm of a given cell plays a negligible role in both 

 diosmosis and permeability. These assumptions are based on 

 indirect evidence. The permeability of the internal cytoplasm 

 of living animal and plant cells has not been investigated by 

 direct methods. 



This paper gives the results of a study of the permeability of 

 the internal cytoplasm and nucleus to dyes and crystalloids. 



The animal material used in this investigation included the 

 eggs of Asterias, Cumingia, Chcetopterus, Nereis and the immature 

 eggs of Necturus, Ameba proteus, Paramecium and the striped 

 muscle and epidermal cells of Necturus. The plants selected 

 were Saccharomyces, Mucbr, Saprolegnia, some five species of 

 Spirogyra, Hydrodictyon, the manubrial cells of Chara, the leaves 

 of Elodea, root-hairs of Vicia faba, Pisum, Hordeum and the 

 parenchyma cells of Tradescantia. 



1 The studies on marine eggs reported in this paper were carried on during the 

 summer of 1912 at the Marine Biological Laboratory, Woods Hole, Mass., while 

 occupying a table through the courtesy of the Director, Dr. F. R. Lillie, to whom 

 I am indebted for many kindnesses. 



I 



