158 THE ENTOMOLOGIST. 



Charpentier also believed that P. migratorius and P. cine- 

 rascens are varieties of one species. 



F. Walker. 



Life-history of Vanessa Polychloros. — In the spring of the 

 year both sexes of this butterfly may be seen toying with 

 each other in our lanes, and occasionally, but less commonly, 

 on the outskirts of woods : impregnation takes places at this 

 season, generally in the month of May, but sometimes as 

 early as April : the ovary of the female is now distended, and 

 the eggs are prepared to receive the fecundating element, but 

 in these and other insects the eggs attain their full size and 

 characters prior to fecundation : in the autumn, on the con- 

 trary, in the ver}' few females I have been able to obtain, 

 there is no distinct appearance of eggs in the ovary ; and 

 neither males nor females exhibit indications of the sexual 

 impulse. The eggs are laid in May, on the twigs of various 

 trees ; the wild and cultivated cherry (Prunus Cerasus, the 

 Cerisier and Griothier of the French) seems the tree chiefly 

 selected in France, and whole rows of these trees may 

 occasionally be seen in July entirely stripped of their leaves 

 by the caterpillars of this species: in England the trees 

 selected are Pyrus Aria (white-beam tree, whip-crop, or white 

 rice), Populus tremula (aspen), Salix capvea (sallow), Salix 

 viminalis and S. vitellina (osiers), and more commonly the 

 different species or varieties of Ulmus (elm). There is some- 

 thing extremely interesting in the manner of oviposition : 

 the female deposits the eggs in crowded patches, often as 

 many as three hundred, and sometimes even four hundred, 

 in number, on the twigs or small branches of the food-plant ; 

 they are distributed all round the twig, com})letely enclosing 

 it, and forming what, in the instance of the lackey moth, has 

 been called an "armlet;" the eggs, however, although closely 

 approximate, are not imbedded in glue, like those of the 

 lackey ; each a^^ seems to possess a distinct operculum, 

 which is forced out of its ])lace and probably eaten by the 

 * young larva on its natal day : each egg has also several, 

 usually eight, longitudinal keels or ridges, but this number is 

 not constant, ibr 1 Jjave some with only seven and others 



