56 BIOLOGY AND ITS MAKERS 



Newton, and also the use of a spring for regulating watches 

 before Huygens, etc. He gave his attention to microscopic 

 study for a time and then dropped it ; yet, although we can not 

 accord to him a prominent place in the history of biology, 

 he must receive mention as a pioneer worker with the micro- 

 scope. His book gave a powerful stimulus to microscopy in 

 England, and, partly through its influence, labor in this field 

 was carried on more systematically by his fellow-countryman 

 Nehemiah Grew. 



The form of the microscope used by Hooke is known 

 through a picture and a description which he gives of it 

 in his Micro gr aphia. Fig. 1 2 is a copy of the illustration. 

 His was a compound microscope consisting of a combination 

 of lenses attached to a tube, one set near the eye of the ob- 

 server and the other near the object to be examined. When 

 we come to describe the microscopes of Leeuwenhoek, with 

 which so much good work was accomplished, we shall see 

 that they stand in marked contrast, on account of their sim- 

 plicity, to the somewhat elaborate instrument of Hooke. 



Grew (1628-1711) devoted long and continuous labor to 

 microscopic observation, and, although he was less versatile 

 and brilliant than Hooke, his patient investigations give him 

 just claim to a higher place in the history of natural science. 

 Grew applied the microscope especially to the structure of 

 plants, and his books entitled Idea of a Philosophical His- 

 tory of Plants (1673) and Anatomy of Vegetables (1682) 

 helped to lay the foundations of vegetable histology. When 

 we come to consider the work of Malpighi, we shall see that 

 he also produced a work upon the microscopic structure of 

 plants which, although not more exact and painstaking than 

 Crew's, showed deeper comprehension. He is the co- 

 founder with Grew of the science of the microscopic anatomy 

 of plants. 



It is not necessary to dwell long upon the work of either 



