Chapter II 



GENERAL FACTS ON THE STRUCTURE OF 



THE PLANT CELL, ITS CYTOPLASM AND 



MORPHOLOGICAL CONSTITUENTS 



The cytoplasm and its permanent inclusions:- In agreement with 

 Strasburger and Henneguy, the term cytoplasm^ is here under- 

 stood to mean all the living matter in the cell with the exception 

 of the nucleus. By the term protoplasm is meant all living matter 

 in the cell, i.e., both cytoplasm and nucleus. The cytoplasm occurs 

 in living cells as a colloidal substance, hyalin and homogeneous, 

 elastic and of a viscosity which is always superior to that of water. 

 This substance holds permanently in suspension a certain number 

 of small elements which resemble bacteria in form and dimensions 

 and are distinguished in living cells by a ref ractivity slightly higher 

 than that of the cytoplasm. These elements, which are called 

 chondriosomes, appear in the form of granules, rods and threads. 



In addition to these elements there are, in green plants, the 

 plastids, whose form is very variable in the algae and which, in 

 higher plants, appear in green tissue as large globules, filled with 

 chlorophyll, which are derived from small elements very similar to 

 chondriosomes in form and histochemical constitution. The cyto- 

 plasm also contains small fluid cavities called vacuoles, composed of 

 water, containing crystalloid and colloidal substances. These vacu- 

 oles, which are very small and very numerous in young cells, swell 

 and usually run together little by little, to form, in mature cells, 



1 Von Mohl designated under the name of protoplasm, the living substance of the cell, 

 i.e., the nucleus and that which in the present volume is called the cytoplasm. But Strasburger, 

 Henneguy. and most of the modern cytologists have reserved the term protoplasm for the 

 cell contents (with the exception of the wall), including the nucleus. Within the protoplasm 

 they distinguish the nucleoplasm or karyoplasm which is the nuclear substance, and the 

 cytoplasm, which is everything else. The term protoplasm, however, is often used as a 

 synonym for that which, in this volume, is termed cytoplasm. Hardy means by cytoplasm 

 all that is not nuclear and he considers the protoplasm to be all living matter within the 

 cytoplasm to the exclusion of the nucleus: the cytoplasm therefore includes the protoplasm 

 and the products of its activity, various inelusions not pertaining to the living substance. 

 BOTTAZZI, on the contrary, incorporated the nucleus into the protoplasm or bioplasm which, for 

 him, includes all the living substance of the cell, i.e.. the nucleus, the living ground substance, 

 which is not nuclear, and the chondriome. He reserves the term cytoplasm for all the cell 

 contents, i.e.. the total protoplasm and all the products elaborated by it. Among these last. 

 BOTTAZZI distinguishes: 1. the metaplasm including the products of cellular elaboration which 

 are permanent (cell walla) ; 2. the paraplasm, represented by the reserve substances or waste 

 products, which are only transitory in the cytoplasm (starch grains, fat globules, etc.), as 

 well as soluble substances formed by cellular metabolism (glycogen, inulin) which may be 

 detected by certain chemical reagents. Thus, for Bottazzi.' protoplasm means all that is 

 living in the cell including the nucleus and the chondriome. whereas the cytoplasm includes 

 the protoplasm and the products of its elaboration (metaplasm and paraplasm). 



