BURMEISTER — HAETIG. 
57 
very different forms of tlie winged and apterous 
insects. 
Schrank was followed by Friedrich Hausmann. 
Although his notices are somewhat heavy, ^ he furnishes 
us with some good and serviceable hints upon which 
he constructed his seven typical forms. Moreover, he 
suggests that during the development of Aphides three 
well-marked life-periods may be traced— if 
momente. 
After this time Zetterstedt paid considerable atten- 
tion to the neuration of Aphis wings, remarks upon 
which are to be found in his ‘ Fauna Lapponica/ but 
unfortunately, like some of his predecessors, he very 
generally ignored the characteristic forms and habits 
of the apterous larvae. He even brought confusion 
into the subject by regarding many winged individuals 
as the males of certain species, although they showed 
but insignificant differences from the ordinary winged 
viviparous females of the same kind. 
Burmeister set forth good grounds for grouping 
various members of this family into genera, and in his 
‘ Handbuch der Entomologie ’ added many new species 
to those already known. Afterwards, with a view to a 
better division into genera. Senator Von Heyden sepa- 
rated off, and placed under his new genus Forda, those 
Aphides which are remarkable for their subterranean 
habits, and are at the same time furnished with very 
short antennae. About this period also the forest- 
ranger, Herr Hartig, published in ‘ Germar’s Zeitschrift 
fur Entomologie,’ Bd. iii, some excellent remarks upon 
the chief distribution of the nervures or veins of the 
Hymmr^ptera genej^^ In accordance with this plan 
he constructed nine genera, and described, though in a 
bald and slight manner, thirty-three species of Aphides. 
Possibly Hartig’s observations 
gestive to Professor J. H. Kaltenbach, of Aachen, who 
* Fried. Hausmann, ‘ Beitrage zu der GescEiclite der Blattlause.’ 
Vide KaltenbacE’s ‘ Introduction,’ to wbicli I am mucli indebted in this 
summary of early authors ; ‘ Monographie der Familien der Pflanzen- 
lause,’ p. vi, et seq. 
^ V 
