OALLIPTERUS QUERCUS. 23 



the eggs of some species of Aphides pass the winter 

 on or under the ground, and the young Aphis com- 

 mences active life at the return of spring warmth as 

 the leaves push forth. 



It has been before noticed that the only memoir 

 on the reproduction and morphology of Aphides 

 in English, which is worthy of the name of a scien- 

 tific treatise, is from the pen of Professor Huxley. 

 In this elaborate paper Professor Huxley points out 

 the significance of the ovarian tubes and the adjuncts 

 which appertain to the perfectly-sexed female; and sub- 

 sequently he shows the representatives of these organs 

 in the chambers of the pseudovaiia, &c., in the vivipa- 

 rous female. To illustrate these latter details, Prof. 

 Huxley selected for experiment the common species 

 Ai^liis pelargo7iii (Siphonojjhora) , and there can be no 

 reasonable doubt of the identity of the species he dis- 

 sected. The same certainty, however, does not appear 

 to attach to the second species chosen to illustrate the 

 evoli^ion of the true ovum. 



Perhaps some knowledge as a specialist is required 

 at once to fix on the salient characters of a particular 

 form of Aphis, and thus there is little cause for wonder 

 that some obscurity attaches to the specific name 

 assigned in this paper by Huxley to the oviparous 

 females he examined. 



At the end of his memoir Professor Huxley, whilst 

 expressing his belief that the Aphides he obtained from 

 the oak were Vacuna drijophila of Schrank, does not 

 speak with complete confidence, but states '' that his 

 insect had certainly seven joints to the antennge." 

 Yet Vacuna certainly has but six, even if we count the 

 nail-like terminal process as one. Again, in the diagnosis 

 of the species, it is stated that the body is covered 

 with setose tubercles, that it has trumpet-mouthed 

 syphons, and that the abdomen is ornamented with 

 transverse rows of dark spots, each row representing a 

 segment. These characters certainly better accord 

 with those of the genus Callipterus than with those of 



