86 DISEASE IN PLANTS. 



was observed and recorded by the writers of the 

 older books of the Bible, half a dozen references 

 to such blights being found in the Old Testament, 

 as well as others to blasted fig trees, etc., in the 

 New Testament. Aristotle, about 350 B.C., noticed 

 the epidemic nature of wheat-rust. The Greeks 

 and Romans were so well acquainted with such 

 diseases that their philosophers speculated very 

 shrewdly as to causes, while the people dedicated 

 such pests to special gods. As regards the Middle 

 Ages, we know little beyond the fact that blights 

 and mildews existed, but Shakespeare's reference 

 in King Lear (Act III., Sc. 4) leaves no doubt 

 as to his acquaintance with mildew in the 1 7th 

 century, and other authorities bear out the same. 

 Even the law took cognisance of the danger of 

 wheat-rust in 1660 in Rouen (Loverdo). Prior to 

 the I 8th century, however, only meagre notes on 

 the subject occur scattered here and there among 

 other matters, and much superstition existed then 

 and later regarding these as other diseases. 



Malpighi, in 1679, gave excellent figures of 

 leaves rolled by insects and of numerous galls, the 

 true nature of which he practically discovered by 

 observing the insect piercing the tissues; previous 

 observers Pliny knew that flies emerge from 

 galls, but thought the latter grew spontaneously 

 having nothing but superstitions and conjectures 

 to offer. Grew, in 1682, also gave a capital 

 figure and description of a leaf mined by " a small 

 flat insect . . . which neither ranging in breadth 

 nor striking deep into the leaf, eats so much only 



