The Substance Which Is AUve in Plants 159 



nate than it might seem, because the constitution of the walls 

 is so closely interlocked with the functions of the cells that from 

 the one we can infer much as to the other. 



Passing now to the cytoplasm we can briefly dismiss it, for, 

 being the typical protoplasm, it has already been fully described 

 in the earlier part of this chapter. It is the working body of the 

 cell, concerned with its nutrition, construction, etc., and the 

 streaming movements are probably concerned with the trans- 

 portation of substances through the cell, a view sustained by the 

 fact that the streaming is most active in general in the cells which 

 are largest. The cytoplasm does not differ particularly in appear- 

 ance in different cells, excepting that it is more fluid in some and 

 more solid in others. One point of present interest about it, how- 

 ever, is this, that just at this time of writing, certain newly found 

 tiny bodies within it, called mitochondria, or chondriosomes 

 are attracting much attention, and may prove to be very im- 

 portant. 



We come next to the nucleus of the cell. It consists of living 



ing the appearance presented by a thin section of cork placed under his microscope. 

 "I could exceeding plainly perceive it to be all perforated and porous, much like a 

 Honey-comb, but that the pores of it were not regular; yet it was not unUke a Honey- 

 comb in these particulars. 



First, in that it had a very little solid substance, in comparison of the empty cavity 

 that was contain'd between, ... for the Inlersiitia, or walls (as I may so call them) 

 or partitions of those pores were neer as thin in proportion to their pores, as those 

 thin films of Wax in a Honey-comb (which enclose and constitute the sexangular cells) 

 are to theirs. 



Next, in that these pores, or cells, were not very deep, but consisted of a great many 

 little Boxes, separated out of one continued long pore, by certain Diaphragms, . . . 



I no sooner discern'd these (which were indeed the first microscopical pores I ever 

 saw, and perhaps, that were ever seen, for I had not met with any Writer or Person, 

 that had made any mention of them before this)." . . . (Robert Hooke, Micro- 

 rraphia, 166.5, 113.) 



Here is von Mohl's sentence, of 1844, in which protoplasm was first named:— "So 

 mag es wohl gerechtfertigt sein, wenn ich zur Bezeichnung dieser Substanz eine 

 auf diese physiologische Function sich beziehende Benennung in dem Worte Proto- 

 plasma vorschlage." {Botanische Zeitung, 1844, page 273); or, in translation, "Ac- 

 cordingly it may be justifiable if for designating this substance I propose an appellation 

 having reference to this physiological function, namely, the word Protoplasm." 



