16 REPORT — 1900, 



constitutes the body and pseudopodia of the Amoeba and other Rhizopoda. 

 As the term ' protoplasm,' as well as that of ' bioplasm ' employed by 

 Lionel Beale in a somewhat similar though not precisely identical sense, 

 involves certain theoretical views of the origin and function of the body 

 of the cell, it would be better to apply to it the more purely descriptive 

 term ' cytoplasm ' or ' cell plasm.' 



Schultze defined protoplasm as a homogeneous, glassy, tenacious 

 material, of a jelly-like or' somewhat firmer consistency, in which numerous 

 minute granules were embedded. He regarded it as the part of the cell 

 especially endowed with vital energy, whilst the exact function of the 

 nucleus could not be defined. Based upon this conception of the jelly- 

 like character of protoplasm, the idea for a time prevailed that a structure- 

 less, dimly granular, jelly or slime destitute of organisation, possessed 

 great physiological activity, and was the medium through which the 

 phenomena of life were displayed. 



More accurate conceptions of the nature of the cell plasm soon began 

 to be entertained. Briicke recognised that the body of the cell was not 

 simple, but had a complex organisation. Flemming observed that the 

 cell plasm contained extremely delicate threads, which frequently formed 

 a network, the interspaces of which were occupied by a more homo- 

 geneous substance. Where the threads crossed each other, granular 

 particles (mikrosomen) were situated. Biitschli considered that he could 

 recognise in the cell plasm a honeycomb-like appearance, as if it con- 

 sisted of excessively minute chambers in which a homogeneous more or 

 less fluid material was contained. The polar and spindle-like radiations 

 visible during the process of karyokinesis, which have already been 

 referred to, and the presence of the centrosome, possibly even during the 

 resting stage of the cell, furnished additional illustrations of differentiation 

 within the cell plasm. In many cells there appears also to be a difference 

 in the character of the cell plasm which immediately surrounds the nucleus 

 and that which lies at and near the periphery of the cell. The peri- 

 pheral part (ektoplasma) is more compact and gives a definite outline to 

 the cell, although not necessarily differentiating into a cell membrane. 

 The inner part (endoplasma) is softer, and is distinguished by a more 

 distinct granular appearance, and by containing the products specially 

 formed in each particular kind of cell during the nutritive process. 



By the researches of numerous investigators on the internal organisa- 

 tion of cells in plants and animals, a large body of evidence has now been 

 accumulated, which shows that both the nucleus and the cell plasm con- 

 sist of something more than a homogeneous, more or less viscid, slimy 

 material. Recognisable objects in the form of granules, threads, or fibres 

 can be distinguished in each. The cell plasm and the nucleus respectively 

 are therefore not of the same constitution throughout, but possess poly- 

 morphic characters, the study of which in health and the changes 

 produced by disease will for many years to come form important mattere 

 for investigation. 



