﻿^6 SEVENTH ANNUAL REPORT 



aourant of the Phylloxera question : The gall-inhabiting type of the 

 Grape Phylloxera is but a dimorphic, agamous and apterous female 

 form, never becoming winged, never producing any males, and not at 

 all necessary to the perpetuation of the species. It can only flourish 

 on a few varieties of vine, and on the others it makes abortive attempts 

 or no attempts at all to found galls. In short, there are but few among 

 the many cultivated varieties of the Grape-vine upon the leaves of 

 which the Grape Phylloxera — under conditions which we shall prob- 

 ably never understand — can form galls ; while on the large majority 

 of our varieties, such as Norton's, Catawba, Goethe, Diana, Cunning- 

 ham, lona, Isabella, Martha, Maxatawney, Ives, ISorth Carolina, etc., 

 we may justly conclude that the insect cannot form galls, since galls 

 are never found upon them. The attempt, therefore, to make the in- 

 sect produce galls upon such vines must necessarily prove futile, and 

 in the light of present knowledge, the first requisite in any experiment 

 having such object, should be an intelligent choice of varieties. 



Even where those vines are employed — as Clinton and varieties of 

 Riparia and Cordifolia — upon which galls can be most readily pro- 

 duced, the experiment of producing galls upon them from root lice, 

 will not be likely to succeed, and the failure to thus produce galls 

 must count for little or nothing against the results already obtained. 



The gall-louse is but a transient form, by no means essential to 

 the existence of the species, and its existence depends not alone on 

 the nature of the vine, but, as already stated, on other yet unknown 

 conditions, which cause it to be abundant on a vine one year and per- 

 haps entirely absent the year following. Now, these conditions may 

 not obtain in one out of a hundred experiments, and the number of 

 fruitless efforts properly and intelligently made to obtain these galls, 

 both in Europe and this country, attest the difficulty here encountered. 

 I have even found the greatest difficulty in producing galls from the 

 progeny of the gall insects themselves, in my experiments in-doors. 



Loose experiments, especially when, as in this instance, they con- 

 vey wrong impressions, do more harm than good. I hope, therefore, 

 that the facts here stated will serve to offset the article in the Depart- 

 ment Reports. 



AVHERE DO THE WIXGED FEMALES LAY THEIR EGGS ? 



Last Fall I was not a little surprised by a letter from my friend 

 Lichtenstein, of Montpellier, France, under date of September 6th, an- 

 nouncing the fact that he had just discovered that the winged Grape 

 Phylloxeroe congregate in immense numbers on the leaves of the 

 Chermes Oak {Quercus cocclfera)^ a small shrubby tree growing on 



