DUBLIN UNIVERSITY ZOOLOGICAL AND BOTANICAL ASSOCIATION. 177 



the Librarian to purchase some books at the auction of their late Presi- 

 dent's library. That a sum of £10 10s. had been received; and several 

 very important works obtained : among others, De Blainville's u Manuel 

 d'Actinologie ou de Zoophytologie," 2 vols.; and "De Malacologie, et 

 des Conchyliologie," 2 vols.; Schlegel, "Essai sur les Serpens," with 

 4to atlas; Balfour's "Botany;" &c. &c. 



A. H. Haliday, A.M., V. P., read a paper, accompanied with figures — 



ON SOME REMAINING BLANKS IN THE NATURAL HISTORY OP THE NATIVE 



DIPTERA. 



The natural history of the Diptera, in particular, as I understand it, is 

 the history of the changes through which they pass, and the manner of 

 life of the larva. Arrived at the perfect state, the winged insect is 

 usually content with light nourishment, such as the nectar drops from 

 the chalice of a flower, the golden dust of the anthers, or the honey-dew 

 with which the leaves are besmeared by colonies of Aphides. Some 

 tribes, indeed, make an exception to this general rule, preying on their 

 weaker kindred with carnivorous appetite, or assailing the larger ani- 

 mals, and man himself, to drain their blood with keen though tiny lan- 

 cets. But the majority, in this stage of their existence, give themselves 

 either to the offices of parentage, as the selection of a proper nidus for 

 their eggs, or to the delights of aerial dances, now associated in the full 

 refulgence of the midday sun, now under the shadow of the forest 

 canopy, suspended over the liquid mirror of the pool, or towering high, 

 in spiral columns, above the summits of the tallest trees, when the 

 lengthening shadows are beginning to invite the cool dews of twilight 

 to descend and refresh the earth again. Far different is the history of 

 that protracted period during which the wingless, legless, wormlike 

 progeny has played its obscure but not unimportant part, unconscious of 

 the more brilliant sphere of life for which it is growing up. Various 

 and widely dissimilar are the situations in which those ' grubs' and 

 ' maggots' obtain, consume, and assimilate the aliment, which is to fur- 

 nish materials for the sinewy muscles and burnished armour, the legs 

 and wings, and the ample and complex eyes of the two- winged fly. 

 But their office in the economy of Nature is no trivial one, and they are 

 fitted to fulfil it by their exceeding fecundity, voracity, and rapidity of 

 growth in general. Linnaeus has said — and it is, perhaps, scarcely an 

 exaggeration — that a couple of flesh-flies will dispose of a bullock as 

 quickly as a single lion could devour the same. In that case and in many 

 others, the part assigned to this order, above all other insects, seems to 

 be that of the scavengers of Nature ; in which capacity, if in some 

 minor instances troublesome to man, they are, to an extent almost in- 

 calculable, conducive to the salubrity and purity of the air he breathes, 

 and the soil he treads on ; however unobservant, in most cases, he may be 

 of the agents or their benefits, or only conscious of disgust when they 

 are forced upon his notice. Many other kinds, however, appear to work 



VOL. IV. 2 A 



