HABITS OF THE APHIDES. 147 



Ptilota, the rasorial order among birds, and the rumi- 

 nating tribe ( Ungulata) among quadrapeds. Dissimilar 

 as these groups are from each other in outward appear- 

 ance, the reader will be nevertheless surprised when he 

 learns how many things they possess in common. One 

 of the chief peculiarities of the Hymenoptera, is their 

 power of producing honey, — a faculty which is given 

 to no other insects but to them and the Aphides : both 

 are eminently gregarious — living in large societies or 

 swarms ; and in both do we find that one female is 

 generally the parent of a whole community, which feed 

 and live together. The wings of the Aphides are clear 

 and transparent ; and the structure of their nervures are 

 more Hke those of hymenopterous insects, than of any 

 other order ; while the Thrips, as we have before inti- 

 mated, bring these groups into immediate contact. 

 Next compare the Aphides with the scansorial and ra- 

 sorial birds ; all these are typically gregarious, feeding 

 only upon vegetables, and uncommonly prolific. The 

 great developement of the tail is one of the chief cha- 

 racters of these birds ; while the Aphides are almost the 

 only Cicades which have caudal appendages. It gene- 

 rally happens, as a necessary consequence of remote 

 comparison, that the more dissimilar are the objects 

 compared, the fainter are their analogies : but some- 

 times this is not the case ; and a remarkable exception 

 to the rule is presented to us on the present occasion. 

 Every one knows that it is from the ruminating ani- 

 mals alone that man derives that healthful and salubri- 

 ous beverage which in the early ages of society formed 

 his chief nourishment. No other vertebrate animal 

 has been intended by nature to supply us with milk. 

 Now, if we look to the annulose circle, and inquire 

 whether Nature has bestowed upon any of these the same 

 power of secreting a fluid destined to feed other crea- 

 tures than its own young, the reply is in the affirm- 

 ative : the Aphides exclusively possess this faculty. 

 When Linnaeus, therefore, with so much reason, termed 

 these little creatures the milch cows of the ants, and 



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