66 The Microscope. 



knowledge my great indebtedness to Prof Carnoy for his kind- 

 ness in placing at my disposal much valuable material for my 

 readers' benefit. In justice, I must also state that I cannot aim 

 at originality, but must often content myself with being only 

 Canon Carnoy's mouth-piece. If I were to try to give a better 

 history of the cell than that given in his " Biology Cellulaire " I 

 must surely fail, and therefore the reader will forgive me when 

 I draw largely from that source. 



I. DISCOVERY OF THE CELL AND ITS PARTS. 



The ;history of the cell begins about the middle of the 17th 

 century (1665), fifteen years after the invention of the micro- 

 scope. Robert Hooke was the first to call attention to the cellu- 

 lar structure of plants. He makes use of the terms " cell " and 

 " pore," and compares the structure of plants to that of a honey- 

 comb. In his Micrographia, 1665, he says: "Our microscope 

 informs us that the substance of cork is altogether fill'd with 

 air, and that that air is perfectly enclosed in little boxes, or cells, 

 distinct from one another." But to Marcello Malpighi and Ne- 

 hemia Grew" we must give the honor of having shown the im- 

 portance of these organic elements, and for having disclosed to 

 men of science the true nature of the cell as known at the time* 

 According to Malpighi's idea, these elements are closed " utri- 

 cles," placed side by side, in order to constitute the entire body 

 of the plant. Grew and Leeuwenhoeck call them "vesicles," 

 and the latter in a letter to the Royal Society of London makes 

 mention also of the cell membrane. A few scientists like Wolff 

 and Mirbel were of the opinion that cells are only simple cavi- 

 ties, formed in the fundamental and independent mass ; other- 

 wise we find it, however, generally admitted, from the time of 

 Malpighi and Leeuwenhoek till Leydig (1856), that the cells are 

 endowed with a solid and distinct wall proper to them, that they 

 are therefore true particles in juxtaposition. Leydig modified 

 this view as we shall see. The terms " utricle " introduced by 

 Malpighi, Grew and Leeuwenhoek, were in use till the time of 

 Brisseau Mirbel, who reintroduced the term " cell " which had 

 been first given to these elements of living bodies by Hooke in 

 1665. This term although erroneous according to the present 

 state of knowledge is now universally used. 



2 In his Anatomy of Plants (Book I. page 4), 1671, Grew says : " It is a body very 

 curiously organized, consisting of an inlinite number of very small bladders," etc. 



