12 PLANT PHYSIOLOGY 



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, as is visible by the Figure B, which represents a 

 sight of those pores split the long-ways. 



Unfortunately for the name which Hooke gave to the cavities 

 he saw, cork is dead. The living substance known as protoplasm 

 is no longer found in cork, and this living material is by far the 

 most important part. Even when Hooke examined the thin 

 slices of living plant tissue he failed to see the cell contents be- 

 cause of their transparency and the imperfections of his micro- 

 scope. The name cell, however, stuck, and even when it was 

 learned that Hooke had never seen the contents of his " cells," 

 the name he gave was extended to include both the chamber 

 and its contents. In fact, according to modern usage, there are 

 many cells without any walls whatever. 



While Hooke is generally given credit for discovering cells, it 

 must be admitted from the drawings seen in the Roger Bacon 

 manuscripts that this thirteenth century Oxford savant by the 

 aid of some microscope of his own invention had seen cells four 

 hundred years before Hooke. 



Malpighi and Grew. — Hooke made no systematic study of 

 plant structures. He was as a child in a strange room who runs 

 from object to object as fancy dictates. In fact Hooke was much 

 more interested in his microscope than in the structures he studied 

 with it. The first systematic study of plant parts was made by 

 Marcello Malpighi (1628-1694), an Italian professor of medicine, 

 who ten years after Hooke 's discovery published an Anatomy of 

 Plants, and by Nehemiah Grew (1641-1712), an English physician, 

 who, after working on the form and arrangement of the cells in 

 various plant tissues, also published an Anatomy of Plants. But 

 neither of these men, who are called the "fathers of plant anat- 

 omy," ever saw the protoplast with its living substance in the cells 

 which they studied. 



Protoplasm. — During the eighteenth century interest cen- 

 tered more in plant naming and classification than in plant struc- 

 tures, and it was not until 1772 that protoplasm was seen by Corti. 

 Various observers had noticed this colorless slimy substance in 

 the cell cavities, but it was not considered important until 1835 

 when Dujardin noted its constant occurrence in certain animals 

 and recognized it as the living material. Purkinje (1839) called 



