RILEY NOTES ON NAT. HIST. OF GRAPE PHYLLOXERA. 265 



after she is born, and on the second day already occupies nearly 

 the whole body, as shown at Fig. 22, a. It is delivered the third 

 or fourth day, and this generally happens independent of impreg- 

 nation. 



This impregnated egg, which I have so far obtained only in my small 

 tubes, is smooth like the other eggs of the species, but more elongated or 

 ellipsoidal, and but very slightly broadest behind. It measures 0.32 mm. 

 and is nearly three times as long as broad. Bright yellow when laid, it 

 soon acquires a deeper, yellowish-green color. The posterior end is gen- 

 erally thickened or roughened by what is probably a mucous secretion 

 that serves to attach it. 



Where this egg is naturally laid I have not yet ascertained, but 

 in all probability it is carried into or near the ground by the im- 

 pregnated parent. The young hatching from it is the normal aga- 

 mous female ; for, though I have not yet hatched this impregnated 

 egg of vastatrix, I have succeeded in doing so with that of Riley 7, 

 and Balbiani long since did so with that of quercus. I am led to 

 think that, once impregnated, the female carries her egg into the 

 ground, because in 1S73 I found females whose abdomens, instead 

 of being filled with numerous small eggs, were distended with a 

 single large one ;* and though I was puzzled to interpret the fact 

 at the time, I have no doubt now that I then had under my eyes 

 the true, impregnated female here described, and that I over- 

 looked the obsolete mouth. 



The habits of these sexed individuals, as I have been able to 

 observe in both the Grape and the American Oak species, are 

 similar to those recorded by Balbiani of the European Oak spe- 

 cies. The male is quite ardent, more active than the female and 

 somewhat longer-lived. 



The complete natural history of the Grape Phylloxera, as set 

 forth in my 7th Report, may now be considered established. A 

 full biological view of the species exhibits to us no less than five 

 different kinds of eggs : 1 st, the regularly ovoid egg, 0.25 mm. long 

 and half that in diameter, of the normal, agamic and apterous fe- 

 male, as it is found upon the roots ; 2d, the similar, but some- 



* One fact, which is not now interpretable, but may have a significance in future, I feel 

 constrained to record in this connection. It is that, in examining vastatrix, I have occa- 

 sionally met with degraded % 's (underground mothers) in which the abdomen, instead of 

 containing numerous small ova, was well-nigh filled with a single much larger egg. Every 

 observed fact leads to others yet unknown and unsuspected ; and the full hist' ry of Phyl- 

 loxera has yet to be written!— C7A Rep., p. 87. 



