334 DISEASES OF PLANTS. 



wood. Boucherie proposed that a solution of pyrolignite of iron 

 should be introduced into trees before being felled, by making perfora- 

 tions at the base^^" tTmnV nr.^1 ni.in^r.n.11 1.1- ------ ' 



cells and vesse 1 

 successful, alth 

 also recommen 



700. Other. 

 purples, or pep d 

 wheat. The ii 

 rnately of a blac 

 corn, but with o 

 spread open, am 

 full of a moist ~s\ 

 under the micro 

 dividuals of the 

 deposit their eggs 



or ten days. He . 



packed in a mode 



vitality long. It 



when moistened w 



tritici, is another c 



a very long retract: 



ings. The Cecido 



and is said to be ve 



are destroyed in nu 



in their bodies. Tl X 



chiformis, attacks 



Peaches. Many oi 



One of this tribe, IE 



of Fayal, one of the 



Tortricida viridan: 



species of Losotae 



the aphis which ct 



so as to have the 



701. Many insects, caiieu 



of leaves, and hollow out tortuous galleries, 



alteration in the colour of the leaves. Galls are caused bylEe~al 

 of species of Cynips, which are provided with ovipositors, by means of 

 which they pierce the bark or leaves with the view of having a nidus 

 for their ova. These galls are very common on the Oak, and are 

 called oak-apples. Sometimes they have one cavity, at other tunes 

 they are divided into numerous chambers, each containing a grub, 

 pupo, or perfect fly, according to the season. Galls are produced on 

 the twigs, catkins, and leaves of the Oak. The artichoke gall of the 

 Oak depends on an irregular development of a bud, caused by the 



