58 (fRAPP: CULTURE AND 



which the gall-type were developed; all extraordinary growth 

 of vine having disappeared before the gall-type had been 

 noticed to any extent. It at least seems probable, that the 

 root-inhabiting form had changed its habit toward that of the 

 gall-louse. 



So soon as this opportunity of studying the relations of the 

 two types were presented, an attempt was made to infect a 

 clean cane of the " Canada" vine with the root-louse com- 

 ing from the " Cornucopia" and appearing upon the surface 

 of the ground. 



A cane was bent from the opposite side of the resistant 

 vine, and its terminal leaves fastened to an infested spot of 

 soil. The leaves and part of the canes were soon covered 

 with young larvae, and a few quiet winged insects; the former 

 passing freely about upon the leaves but forming no galls, or 

 at least only doubtful or abortive attempts. Some of the 

 young leaves upon the infested canes, were pierced by young 

 larvae, which had settled just outside of the fresh galls, and 

 had remained until a red dead spot had been formed. 

 Others of the larvae were seen crawling about; but they did 

 not seem to establish galls. Contrary to the usual habit of 

 the gall-louse, they kept mostly upon the under side of the 

 leaf. 



In fact, there were very few galls formed except upon the 

 smallest leaves. One of these delicate leaves, an inch 

 square, bore about thirty galls, a large proportion of which 

 contained young larvae, which were -easily seen by looking 

 through the leaf toward the light. Some galls even contained 

 the mother, larvae, and eggs. 



It thus appears that, at least so late in the season, the 

 change of habit from root to leaf is not readily made. 



ENEMIES TO THE PHVLLOXERA. Of the known ene?nies to 

 the phylloxera, only two forms were identified during our ob- 

 servations. The phylloxera thrips were seen passing about in 



