8 Roberts, On two cases of Parallelism in the Aphides . 



time. I believe the affected leaves fell off the tree shortly 

 afterwards, and I have no further note of observation of 

 the species until January 9th of the present year. On 

 that date, after several fruitless searches, I succeeded in 

 finding the winter form (hiemalis), most individuals of 

 which were situated singly near the base of a leaf bud, 

 though one or two were on other parts of the twig. They 

 were of yellowish brown colour, with the legs and antennae 

 black, though these are not visible until the insect is 



Text-Jig. 3. — Hamamelistcs (tc/lgreni, Meijere. 

 Position of hiemalis at base of birch bud. 9/i./i 5. Length about 1*1 mm. 



turned over, being enclosed by the expanded dorsal area. 

 In length the hiemalis is about i*i mm. The dorsal 

 surface is somewhat roughened by the waxy secretion 

 given off and is considerably arched to the median line, 

 where some traces of segmentation are visible. 



Borner (7) gives a diagram illustrating the life cycle 

 of H amamelistes betnlinus^ Horv., in which the winged 

 sexuparae appear as the offspring of the first summer 

 generation of apterous 9 9 (aestivales I.) and makes his 

 aestivales II. as a parallel generation to the sexuparae. 



