Insects. 4487 



Hedychrum ardens. Lul worth, Portland. 



„ n. s.? (allied to aeneum). Blandford, and near 



Barnstable. 



Elampus Panzeri, Portland Sands by Chesil Bank. 

 Chrysis austriaca. Glanville's Wootton, Powerstock, and Cam- 

 bridge. 



J. C. Dale. 

 Glanville's Wootton, 

 June, 1854. 



Researches on the Development of Viviparous Aphides. 

 By Waldo T. Burnett, M.D.* 



Every naturalist is aware of the remarkable phenomena connected 

 with the viviparous reproduction of Aphides or plant-lice, for their 

 singularity has led them to be recounted in works other than those of 

 natural science, and, from the days of the earlier observers, they have 

 been the theme of a kind of wonder-story in zoology and physiology. 



I need not here go over the historical relations of this subject. 

 The queer experiments and the amusing writings of the old entomo- 

 logists are well known. The brief history of the general conditions of 

 the development of these insects is as follows : — In the early autumn 

 the colonies of plant-lice are composed of both male and female indi- 

 viduals ; these pair, the males then die, and the females soon begin 

 to deposit their eggs, after which they die also. Early in the ensuing 

 spring, as soon as the sap begins to flow, these eggs are hatched, and 

 the young lice immediately begin to pump up sap from the tender 

 leaves and shoots, increase rapidly in size, and in a short time come 

 to maturity. In this state it is found that the whole brood, without a 

 single exception, consists solely of females, or rather, and more pro- 

 perly, of individuals which are capable of reproducing their kind. 

 This reproduction takes place by a viviparous generation, there being 

 formed in the individuals in question young lice, which, when capable 

 of entering upon individual life, escape from their progenitor, and 

 form a new and greatly increased colony. This second generation 

 pursues the same course as the first, the individuals of which it 

 is composed being, like those of the first, sexless, or at least without 

 any trace of the male sex throughout. These same conditions 



* Extracted from Silliraan's Journal for January, 1854. 



