70 EBfSIUIA/irs OUTLINES OF 



and there a few eggs. The larvre thus hibernating become 

 dingy, with the body and limbs more shagreened and the 

 claws less perfect than when first hatched; and. of thousands 

 examined, all bear the same appearance, and all are fur- 

 nished with strong suckers. As soon as the ground thaws 

 and the sap starts in the spring, these young lice work off 

 their winter coat, and growing apace commence to deposit 

 their eggs. Since, in 1870, the absolute identity of these 

 two types was proved by showing that the gall-lice become 

 root lice. The fact has been repeatedly substantiated by 

 different observers. (In 1873 galls were obtained on the 

 leaves of a Clinton vine from the root-inhabiting type, thus 

 establishing the identity of the two types.) 



THE MORE MANIFEST AND EXTERNAL EFFECTS OF 

 PHYLLOXERA DISEASE. 



The result which follows the puncture of the root louse 

 is an abnormal swelling, differing in form according to the 

 particular part and texture of the root. These swellings, 

 which are generally commenced at the tip of the rootless, 

 eventually rot, and the lice forsake them and betake them 

 selves to fresh ones — the living tissue being necessary to 

 the existence of this as of all plant lice. The decay affects 

 the parts adjacent to the swellings, and on the more fibrous 

 roots cuts off the supply of sap to all parts beyond. As 

 these last decompose, the lice congregate on the larger 

 ones, untL at last the root system literally wastes 

 away. 



Remedies. Thus far, the only practicable method of 

 combating the insect when established upon the root, is by 

 drowning it by irrigating the soil. In Europe the method 

 largely adopted is to graft their vines upon varieties, the 



