52 THE CANADIAN ENTOMOLOGIST. 



there was no fear exhibited, nor did she fly away, but stood on the outside of 

 the wall while I examined the interior. 



One part of the history of this species, I am sorry to say, I have not had 

 an opportunity to investigate — that is, their economy while in the second 

 nest, for I believe that it is during this stage of progress that a true account 

 of the individuals which constitute the colony can be determined. Here we 

 could, no doubt, arrive at some conclusion regarding 'the correct dates of the 

 appearance of the sexes which are said to occur towards the autumn. Reau- 

 mer states that there are two sizes among the males. It would be interesting 

 to know if they are permanent kinds. Kirby, and other writers on Insects 

 (see Westwood's Int. to the Modern Class, of Insects), states that the neuters, 

 or what are now termed undeveloped females, i( massacre the later brood of 

 larvoe which are not able to undergo. their transformation before the setting 

 in of the winter/' This may, no doubt, be the end of the later larvae of the 

 two species here spoken of, but it is not the case with the pupae which occupy 

 the cells of V. metadata in the autumn, as I procured living specimens from 

 nests brought home in October. The second nest of V. germanica contains 

 two tiers of cells, which are generally enveloped with six or more partitions. 

 During the warm season in which it is occupied, proper ventilation is neces- 

 sary t> insure the health and increase of the colony; therefore the wasps 

 never neglect this important mode by which the interior is kept at an equal 

 temperature. The innermost partition encircles the double tier of cells, but it r j 

 aperture is larger than the next outermost, and the aperture of each decreases 

 towards the exterior one until it is only of sufficient size to admit one or two 

 insects. In order that pure air be properly obtained, and that the circulation 

 should be sufficient to force foul air from the interior, we find other apertures 

 on the exterior partition, which lead in zig-zag passages from one partition 

 to another until they reach the interior. This mode of ventilation is beauti- 

 fully illustrated in the large autumnal nests, and for a good reason, we gener- 

 ally find them containing from four to five tiers of cells and a numerous colony, 

 which obtains its full strength in this nest. In a nest lately examintd the 

 latter number of tiers was found; the two uppermost consisted of small cells, 

 and those of the two central were of larger dimension, and had been evident- 

 ly occupied by males and females, while the fifth or lowermost tier does not 

 appear to have been occupied; but it is nevertheless curious that it agrees 

 in size, number and form of cells to that f.und in the parent nest in spring. 



Notwithstanding the powerful sting with which some of them are provided, 

 wasps are liable to the attacks of other insects, and their nests are entered by 

 parasites belonging to the orders of Coleoptera, Hymenoptera and Diptera, 

 for the purpose of depositing their eggs in the cells containing the larvae. 



