CHAP, i.] by Malpighi and Grew. 245 



germination, and many on the structure of different woods. 

 But all bears the stamp of only occasional study of plants ; 

 he was led to his observations by questions of the nature- 

 philosophy then in vogue, and especially by such as were 

 connected with the theory of evolution, not unfrequently by 

 mere curiosity and pleasure in things obscure and inaccessible 

 to ordinary people, but he did not gain from them a general idea 

 of the structure of plants. In the course of these observations 

 he did unquestionable service in perfecting simple magnifying 

 glasses ; he made a large number with his own hands, and 

 these possessed magnifying powers evidently not at the 

 command either of Malpighi or Grew. By aid of such 

 glasses he discovered the vessels of secondary wood which 

 are not spirally thickened but beset with pits, the true 

 character of which however he did not investigate. He 

 was the first moreover who perceived the crystals in vegetable 

 tissue, namely in the rhizome of Iris florentina and in species 

 of Smilax, and this could only be done with strong magnifying 

 powers. In other matters he repeats the histological views of 

 Malpighi and Grew, and on the whole his numerous com- 

 munications seem painfully fragmentary and unscientific in 

 presence of Malpighi's elegance and perspicuity, and Grew's 

 systematic thoroughness. His figures too, which were not 

 drawn by himself, are with some exceptions inferior to those 

 of his great contemporaries. 



