02 BRITISH AMIDES. 



abdominal cavity contains a single egg which is the 

 true ovum. The female delivers herself of it about 

 the fourth day after she is hatched, and this without 

 any real necessity of concourse with the male. Whether 

 such eggs are barren it does not appear (see Riley, 

 Eighth Report, p. 159). The true ovum is larger 

 than all the preceding pseudova. It is yellow at first, 

 but soon afterwards it becomes olive in colour with 

 a rough exterior. Its survival through the winter in 

 the crevices of the bark has been substantiated by Dr. 

 Balbiani and M. Lichtensteiu, and there is no doubt 

 that the fundatrix is the produce of the same, just as 

 with all other Aphides. 



It has been stated that the Phylloxera keeps below 

 the soil in dry weather, but ascends the stocks in the 

 wet season (Villedieu). 



M. Lichtenstein lays much importance on the fact 

 that the males and females remain for several days 

 after they have been deposited by the winged insect 

 in certain delicate membranes, which at one time he 

 regarded as cocoons. ' The reason why he now con- 

 siders these egg-like bodies as pupaa (nom donne par 

 Latreille aux chrysalides qui sont formee par la peau 

 de la larve se durcissant autour de 1'animal) will be 

 found in the general summary of the genus Phylloxera, 

 with which he has obliged me. 



I gather from his remarks that, when two winged 

 generations appear in Phylloxera, the first produces a 

 rostrated progeny, and the last a non-rostrated. If 

 the vine Phylloxera shows but one alate generation, 

 it furnishes the non-rostrated sexes, in the autumn. 

 He warns all investigators against the confusion likely 

 to arise by confounding an alate insect with its later 

 winged successor. 



If there be no aerial forms in a cycle, the foundress 

 descends at once to the roots and no galls appear on 

 the leaves. 



In concluding my diagnosis of such Phylloxeridaa as 

 have come to my notice, I introduce to the reader the 



