82 



SCIENCE-GOSSIP. 



Before dealing with the species it is desirable to 

 explain in detail the terminology of this stage of 

 the insect. With this intention the accompanying 

 figures, with many others, to illustrate these 

 articles, which are expected to extend to four 

 numbers of Science-Gossip, have been especially 

 drawn by Mr. Walter A. Pearce. Fig. A is a dia- 

 gramatic view of the pupa of Libellula depressa. 

 Fig. B is the " mask " of an ZEschna showing the 

 mandibles and their processes. The three draw- 

 ings under fig. C represent the female valves of 

 (m) Libellulinas, (n) .ZEschninae and (o) of the 

 Agrioninae. 



The parts of the body of the various species will 

 hereinafter be referred to according to these figures, 

 which will act as a key to the nomenclature. 



A question of great interest has been raised by 

 Mr. Harcourt Bath in "The Garner and Naturalists' 

 Gazette" for March, 1892, and again in Science- 

 Gossip for February, 1893, He notices the fact 

 that Dragon-fly larvae occur in many places, such 

 as small artificial ponds which entirely dry up in 

 hot weather. The conclusion is that the larvae 

 found therein during the season following are the 

 outcome of eggs laid by the mature females on the 

 surface of the mud, where the eggs remain un- 

 hatched until a sufficient supply of rain again 

 converts the hollows into ponds. 



( To be continued.) 



Wasps' Nest. — Two Davs' Work. 



A STUDY OF WASPS' NESTS. 



HHHIRTY-FIVE years ago, in the "Entomologists' 

 Weekly Intelligencer," appeared some articles 

 by Mr. S. Stone, of Brighthampton, in Oxfordshire, 

 entitled "A Recipe for obtaining Specimens of 

 Wasps' Nests in various stages of formation." I 

 remember reading them at the time with much 

 interest and with the firm resolution that when 

 opportunity offered some similar experiments should 

 be conducted by me. That opportunity has not 

 yet arrived, but it was with much pleasure I 

 noticed the other day that the British collection at 

 the Natural History Museum in South Kensington 

 still includes a series of wasps' nests which had 

 been cultivated by Mr. Stone. These are in good 

 condition and well worth}' of examination. Two of 

 them are here figured. 



Mr. Stone's " recipe " commenced with instruc- 

 tions for the preparation of several little excavations 

 in a dry bank in some locality frequented by wasps. 

 The object of these holes was to tempt the females in 

 springtime to commence building their nests under 

 his guidance. In this Mr. Stone seems to have 

 been very successful, for he speaks of having 

 twenty colonies under his observation which he 

 had removed to various rooms of an unoccupied 

 house. It will be best without further remark- 

 to quote Mr. Stone's own words, because the 

 magazine in which they 

 appeared is not now 

 generally accessible. 



" Choose a bank, the 

 dryer the better, in which 

 form a number of chambers 

 a few yards apart. These 

 chambers should be oven- 

 like excavations, some five 

 or six inches in diameter. 

 Having formed a chamber, 

 insert a small wooden peg 

 in the centre of the roof 

 to which the nest will be 

 attached. Close up the 

 mouth of the excavation 

 with clay, leaving only an 

 aperture sufficient for the 

 entrance of the insect for 

 whose use it has been 

 prepared. They (the 

 chambers) should be ready 

 for occupation before the 

 end of April and on to the 

 end of May. . . . The 

 season having arrived for 

 the insects to commence 

 their labours, let inspection 

 of the various excavations 

 be at once proceeded with. 

 By removing the clay 

 ' stopper ' from the mouth 

 of No. 1 you will be enabled 

 to see at a glance whether 

 a nest has been begun, 

 and if such should prove 



