1048 The Zoologist — January, 1868. 



supposing thera those of affinity. No one could support such a theory. 

 Was it intended that each species should be attended by another 

 species intimately allied to it ? No one ever doubted such a principle. 

 In the opening part of his paper, Mr. Newman had alluded to the 

 binary divisions of the higher groups, such as Vertebrata and In- 

 vertebrata, Ptilota and Aptera, &c. ; but in the latter part he had con- 

 fused these relations (vague as they ofteu were) with the closest possible 

 affinity that could exist in nature, exclusive, of course, of that between 

 individuals of the same species." 



Mr. Westwood's profound remarks were received by the Meeting 

 with almost tumultuous approbation : I confess myself unable to see 

 their exact drift, probably owing to my not being sufficiently advanced 

 in the study of affinities and analogies. ' 



Believe me, my dear Mr. Wollaston, 



Most faithfully yours, 



Edward Newman. 



PS. My next letter will, I trust, present a little more of novelty, 

 as the subject has scarcely been considered as regards Lepidoptera. 

 I call the letter " Eugenesic Races." 



Notes on Aphides. By F. Walker, Esq., F.L.S. 



Knowledge of the Aphidida; is more difficult of attainment and 

 requires more persevering study than that of any other tribe of 

 insects, on account of their migratory habits and ever-varying forms, 

 and consequent frequent appearance in new aspects. A translation of 

 the latest systematic arrangement of them,* with references to olliur 

 works on the same subject, may serve as a guide to the investigation of 

 the family. 



ArniDiD^:, Passer in I. 



A. Antenna; seven-jointed 1. Ai'HiDiN/E. 



AA. Antenna; six-jointed, at least in the winged form.f 



* 'Gli Afidi con un prospetto dei generi ed alcune specie nuove italiane,' par 

 Giovanni Passerini. 18G0. ' Aphididae Italiiae Lucusque obseivata;,' a J. Passerini, 

 M.D. 1863. 



f When the winged form of a genus is known the character of the antenna? is 

 especially to he sought for in this form, for in some genera the apterous form has four- 

 jointed or five-jointed antennae and the winged form has six-jointed antenna;. — 

 Passerini. 



