86 HYMENOPTERA 



destroyed and reformed, as the combs they contain increase in 

 size. Marchal's observations ^ relate chiefly to the production of 

 the sexes and worker-forms, in the subterranean species, Vespa 

 germanica and V. vulgaris. The layers of comb include cells of 

 two sizes. The upper layers, which are the first formed, consist 

 of small cells only : the lower combs are constructed (at Paris) 

 early in August, and consist of larger cells from which males 

 and large females are reared. The males are, however, reared 

 also in largo numbers in the small cells. If the queen be re- 

 moved, the woi'kers become fertile, and produce parthenogenetieally 

 many eggs, but all of the male sex. He entertains no doubt 

 that even when the queen is in full vigour the workers produce 

 males if there is an abundant food supply. 



The social wasps at present known number 500 or 600 species. 

 Polistes is a very extensive genus, and it has also a very wide 

 geographical distribution ; some of the species — and those found in 

 widely-distant parts of the world — are remarkable on account of 

 their excessive variation in colour, and it is worthy of note that the 

 extreme forms have been more than once taken from the same nest. 



Next to Polistes, Vespa is the most numerous in species, 

 about 150 being known, and it is to this genus that all our 

 British social wasps belong. No Insects are better known 

 in our islands than these wasps, owing to the great numbers 

 of individuals that occur in certain seasons, as well as to 

 their frequently entering our habitations and partaking of our 

 food, and to the terror that is occasioned by their supposed 

 ferocity and desire to sting. This last feature is a complete 

 mistake ; wasps never sting unless they are roused to do so by 

 attacks, or by considerable interference with their work. The 

 only real danger arises from the fact that a wasp may be occa- 

 sionally taken into the mouth with fruit, or may be handled 

 unawares. When they are flying about they are perfectly 

 harmless unless attacked or irritated, and even if they settle 

 on the person no danger of their stinging exists unless move- 

 ment is made. Sichel correctly states that a person may 

 station himself close to a wasp's nest and remain there without 

 any risk at all, provided that he makes no movement ; indeed, it 

 is more than probable that if no movement, or if only gentle 



' GR. Ac. Paris, cxvii. 1893, p. 584 ; o}). cit. cxxi. 1895, p. 731 ; Arch. Zool. 

 exper. (3) iv. 1896, pp. 1-100. 



