298 HISTORY OF BOTANY. 



tonia pini). The yellowish green caterpillar shews itself in 

 incredible numbers, and destroys the cones completely. 



429. 



Among gnats and flies we mention, first, the Musca pumi- 

 lionis, Bierk., or the Mos'illiis arcuattis, Latr. This fly lays 

 hold of the Wheat and also of the Rye crops, while they are 

 young, but these frequently shoot out more luxuriantly af- 

 terwards ; (Spence and Kirby, Introd. to Entom. i. p. 170.) 

 A small yellow gnat, Tipula tritici, eats into the blossoms of 

 Wheat, and destroys them ; (Linn. Trans, iii. p. 242.) 

 Lastly, we may enumerate, among the unwinged insects, the 

 small red acarus of our hot-houses {Acai'us telarius), which, 

 when enough of air is not given to the plants, or when they 

 are kept too warm, overspreads them with a fine web, and so 

 destroys them. 



CHAP. VIL 



HISTORY OF BOTANY. 



I. Aticient History till the Revival of Science, 



430. 



Scientific Botany is indebted for its origin to the philoso- 

 phical schools of ancient Greece. But it was the physics of 

 plants, much rather than descriptive botany, which was then 

 cultivated, because, in the first place, from the small number 

 of plants which were then known, and which, among the 

 Greeks and Romans, scarcely exceeded a thousand, it was 

 not found necessary to think of classifying them, — of forming 

 a theory for this purpose, — of arranging them according to a 

 scientific system, — and of giving them a regular nomenclatuie ; 

 secondly^ Because the views of the ancients, with respect to 



