THE ANNALS 



AND 



MAGAZINE OF NATURAL HISTORY. 



[SECOND SERIES.] 

 No. 4. APRIL 1848. 



XXIV. — Descriptions 0/ Aphides. By Francis Walker, F.L.S. 



Yet e'en decay and darkness have their world ! 



Nothing is lost, — nothing forsaken here : 



In dull rank weeds unnumbered hosts lie ourl'd — 



Root, branch, stem, flower, have each their insect sphere ; 



E'en darkness hath its population drear ; 



Each turf impregnate with existence heaves ! — 



More countless metamorphoses appear — 



More marvels haunt our feet than thought conceives. 



While worlds of insect tribes hang quivering on the leaves. — Swain. 



La providence, en livrant l*homme a lui-mSme, I'a plac6 sous une grande 

 et redoutable responsibility. Si I'^tude de I'histoire naturelle n'avoit servi 

 qu'a prouver cette verity, elle auroit atteint le but le plus noble dont les 

 sciences puissent s'enorgueillir, celui de tendre k am^liorer I'espece humaine 

 par les exemples qu'elle nous propose. — Ruber. 



This communication, instead of being introduced with remarks 

 on the family of Aphides or on the authors who have noticed 

 them, begins with particular observations and specific descriptions 

 as a groundwork for generalities, and as a means of gradually 

 unfolding the history of these insects, and of gathering matter 

 for satisfactory conclusions thereon. 



First Group. 



This comprises the two following species, and is characterized 

 by some parfes of their structure, such as the great length of the 

 nectaries and of the last joint of the feelers, by their being scat- 

 tered and not clustering on their habitation, and by their three 

 forms, which are — 



1. The viviparous winged female. 



The name of this form indicates one of the peculiarities of 

 Aphides, nearly all other insects being oviparous, and its indivi- 

 dual power of self-reproduction is a still more remarkable pro- 

 perty. This continual renewal, whose period may in some cases 



Ann. ^ Mag. N. Hist. Ser. 2. Vol. i. 17 



