﻿98 SEVENTH ANNUAL REPORT 



less extent,ju8t as most plants annually produce a superabundance of 

 seed, the larger proportion of which is destined to perish. From a 

 large number of facts that have come to my knowledge in insect-life 

 I actually believe this to be the case; and, if so, it adds one more 

 weighty reason to those I have already given why the insect is so in- 

 jurious in France, and explains its rapid multiplication in the thickly 

 planted vine districts of that country. There, few winged insects 

 would fail to settle where their issue could survive ; while in our 

 country there must be, on this hypothesis, an immense number an- 

 nually perishing in the large tracts of other vegetation between our 

 scattering vineyards. 



The particular part of the vine chosen by thege winged mothers, 

 when they settle in a vineyard, for the deposition of their eggs, has 

 not yet been definitely ascertained. "In confinament I have had such 

 eggs deposited both on the leaves and on the buds, and from the pre- 

 ference which, in ovipositing, these aerial mothers showed for little 

 balls of cotton placed in the corners of their cages, I infer that the 

 more tomentose portions of the vine, such as the bud, or the base of 

 a leaf-stem, furnish the most appropriate and desirable nidi. On this 

 hypothesis it is quite possible for the insect to be introduced from 

 vineyard to vineyard, or from country to country, as well upon cut- 

 tings as upon roots." — [6th Rep. p. 46. So I wrote a year ago ; but 

 while these eggs may frequently be laid upon the vine itself, I am now 

 disposed to believe that they are more often laid in the minute cracks- 

 and interstices on the surface of the ground, especially near the base 

 of the vine ; for where I have had the females confined in tubes or 

 bottles half filled with moist earth, they have often deposited in the 

 interstices at the sides of the vessel, and, as Balbiani has remarked,, 

 the constant elongation of the abdomen, and tentative motion of the 

 tip from side to side, which is common to these winged mothers, rather 

 indicate search for some such positions. 



THE SEXU^il. IXDIVIDU^UvS. 



We have seen that the winged females abound, especially during: 

 August, and that they deliver themselves freely of their egg like con- 

 tents. They are quite active during the warmer parts of the day and 

 are comparatively short-lived, at least in confinement, where they 

 usually die along side their eggs. These eggs are twice as long as 

 wide, the lar-^er ones, which produce females, about 0.025 inch and the 

 smaller 0.018 inch long. They are quite pale and translucent and soon 

 begin to show the reddish eyes of the embryon within. They hatch,. 



