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 played in the life 

 of the cell by the viscous matter known vaguel}* up to that time 

 as schleim, or mucus, Mohl points out the essential identity 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 physiological 

 grounds, the significant name protoplasma. 



For convenience of reference, the paragraph in which the word 

 is first employed is here given : 



" Da wie schon bemerkt diese zahe Fliissigkeit uberall, wo Zellen 

 entstehen sollen, den ersten, die kiinftigeu Zellen andeutenden festen 

 Bildungen vorausgeht, da wir ferner aimehmen miissen, dass dieselbe 

 das Material fiir die Bildung des Nucleus und des Primordialschlauches 

 liefert, indem diese nicht nur in der nachsten raumlichen Verbindung 

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

 dass also ihre Organisation der Process ist, welcher die Entstehung der 

 neuen Zelle einleitet, so mag es wohl gerechtfertigt sein, wenu ich zur 

 Bezeiclmung dieser Substanz eiue auf diese physiologische Function 

 sich beziehende Benennung in dein Worte Protoplasma vorschlage." l 



In 1835 Dujardin described a contractile substance capable of 

 spontaneous movement in certain of the lower animals, to which 

 he gave the name Sarcode. The identity of sarcode with that 

 substance which forms the essential body of animal cells and 

 with 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- 



* cu 



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 by Henry Smith for the Sydenham 

 Society, 1847). 



1 Botanische Zeitung, 1846, p. 75. 



2 Archiv fiir Anatomie, Physiologic, und vviss. Medicin, 1861, pp. 1-27, and 

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



