EDGEWORTH — ON IRISH VESPIILE. 97 



Again, I shall show that those phenomena are not presented which 

 we should expect from the presence of 30,000 Wasps. I find by obser- 

 vation that each "Wasp occupies about twenty minutes in each journey, 

 and remains about twenty minutes in the nest after he has come in, and 

 therefore each "Wasp passes the entrance of the nest three times an hour ; 

 therefore the number of Wasps in any nest is a third of the sum of exits 

 and entrances observed in an hour; or, conversely, the sum of exits and 

 entrances is three times the number of Wasps. Accordingly, in a nest 

 of 30,000, the number of exits and entrances would be 90,000 per hour, 

 or 1500 per minute, and such a nest, I believe, has not yet been ob- 

 served. I should also add that I have seldom seen a nest which con- 

 tained 2000 wasps. Mr. Smith has seen one with 2590 ; but it is very 

 possible that climate may affect the size of Wasps' nests very consi- 

 derably. 



The nests of Wasps vary in size very much, according to the favoura- 

 bleness of the weather. In dry seasons they are generally larger. The 

 mildness of April and May, not so much as the number of queens seen 

 in the spring, or tbe quantity of nests the preceding year, seems to 

 affect the number of nests for the present year. Wasps are very delicate 

 animals, and peculiarly subject to the influence of the weather ; but the 

 severity and wet of winter itself do not appear to affect their number 

 the following summer. It is impossible, at least from such circum- 

 stances, to predict the number or the paucity of Wasps. Such, at least, 

 is my experience, confirmed by carefully comparing the various notices 

 in the "Zoologist," which form valuable statistics on this point. In 

 1848 the total number of queen Wasps captured was the almost incred- 

 ible amount of 14,750, weighing sixty-three ounces. It is to be re- 

 gretted that the various species of Wasps to which these belonged were 

 not determined. It is most probable that few of them, or at least com- 

 paratively few, were V. vulgaris — in reality the only formidable species, 

 as that species has few queens, both in proportion to its nest and its 

 crowd of workers. 



Vespa Germanica seems to be almost a variety of V. vulgaris ; at any 

 rate, the habits of the two are so similar, that one description will an- 

 swer for both. Vespa vulgaris is the common Wasp of Ireland; but in 

 the county of Down, Mr.Haliday assures me that V. rufa is more com- 

 mon. 



I give no description of this or any other Wasp, as Mr. Smith has 

 completely exhausted the subject; but it is worthwhile remarking that 

 the colour and size of this insect seem to depend very much upon the 

 locality in which its nest is situated. I have observed that nests which 

 face the sun generally produce small, bright yellow, very active Wasps ; 

 whereas the Wasps from nests in dark and shady places appear larger, 

 darker, and lazier. The same phenomenon is to be seen among Ants — 

 some being lighter, and some darker than others, without any other very 

 apparent cause than that suggested by the situation of their nest. It 

 has also been remarked that each individual Wasp, as he grows older, 

 alters considerably in size and colour. 



