220 PROTOPLASM. 



not SO much with the movement of what would to-da}- be called 

 cell-sap, as with the general behavior of all the motile contents 

 of active vegetable cells. After showing that his predecessors 

 had not clearly understood the important part plaj-ed in the liffe 

 of the cell by the viscous matter known vaguely up to that time 

 as schleim, or mucus, Mohl points out the essential identitj- of 

 the nucleus, primordial utricle, and the basic substance filling all 

 but the sap-cavities of the cell. For the substance which is 

 essential to the formation of every new cell and to the develop- 

 ment of newly formed cells he proposed, upon phj-siological 

 grounds, the significant name protoplasma. 



For convenience of reference, the paragraph in which the word 

 is first employed is here given : — 



"Dawie schon bemerkt diese zahe Fliissigbeit iiberall, wo. Zellen 

 .entstehen sollen, den ersten, die kunftigen Zellen andeutenden festen 

 Bildungen vorausgeht, da wir ferner annehmeu miisseu, dass dieselbe 

 das Material fiir dieBildung des Nucleus uiid des Primordialsclilauehes 

 liefert, indem diese nicht nur in der niiohsten raumlichen Verbinduiig 

 mit derselben stehen, sondern auch auf Jod auf analoge Weise reagiren, 

 dass also ihre Oi'ganisation der Process ist, welclier die Entstehung der 

 neuen Zelle eiiileitet, so mag es wolil gerechtfertigt sein, weun ich zur 

 Bezeiclmung dieser Substanz eine auf diese pliysiologische Function 

 sich beziehende Benennung in dem Worte Protoplasma vorschlage." i 



In 1835 Dujardin described a contractile substance capable of 

 spontaneous movement in certaiu of the lower animals, to whicli 

 he gave the name Sarcode. The identit3- of sarcode with that 

 substance which forms the essential body of animal cells and 

 Vith the protoplasm of vegetable cells was suggested by several 

 investigators and finally demonstrated by Max Schultze in 1861.^ 



Schwann, even as early as 1839, pointed out various analogies 

 and homologies between animal and vegetable cells, and enun- 

 ciated the following proposition : animal cells are completely 

 analogous to vegetable cells, and are quite as independent in 

 their mode of growth. The bearing of Schultze's demonstra- 

 tion upon the foregoing proposition is obvious. Schwann 

 instituted also certain comparisons between the mode of forma- 

 tion of cells and that of crystals ("Microscopical Researches 

 into the Accordance in the Structure and Growth of Animals 

 and Plants." translated b}- Henry Smith for the Sydenham 

 Society, 1847). 



1 Botanisclie Zeitung, 1846, p. 75. 



" Arohiv fiir Anatomie, Physiologie, und wiss. Medicln, 1861, pp. 1-27, and 

 Das Protoplasma der Rhizopoden und der Pflanzenzellen, Leipzig, 1863. 



