1905.] 277 



tlie basnl lialf of tlie abdomen is banded wit!; bi-ovvn, while the apex 

 is shining bhick or blackish-brown. The males are readily recognisable 

 owing to the presence of a peculiar strncture at the tip of the first 

 joint of the front tarsus, on the inner side. Under an ordinary 

 plalyscopic lens the structure in question looks like a speck of black 

 dirt, but when examined under a compound microscope it is seen to 

 consist of a comh comjjosed of some twelve or thirteen stout black 

 teeth, and set obliquely to the long axis of the tarsal joint. This 

 peculiar organ is figured by Howard in '• The Principal Household 

 Insects of the United States" (U. S. Dept. of Agriculture. Div. of 

 Entomology. Bulletin No. 4. New Series, Kevised Edition : 1902), 

 p. 110, fig. 51, where also the adult insect and its transformations 

 are shown. The full-grown larva is an active yellowish-white maggot, 

 about 4 mm. long, with the usual conspicuous black mouth-hooks, and, 

 at the hinder end of the body, a pair of prominent posterior spiracles, 

 orange in colour, and situated upon a backwardly directed protuber- 

 ance from the upper edge of the terminal segment. The puparium is 

 yellowish, about 3 mm. in length, with the larval posterior stigmata 

 prominent at the hinder end, and at the anterior extremity, on the 

 upper side, a flattened depression, truncated in front, with the 

 branched larval cephalic spiracles projecting from its angles. 



Like other species of Drosophila, D. melanogaster breeds in 

 decaying or fermenting fruit and other vegetable matter ; it is also 

 attracted by, and breeds in, fermenting liquids, which perhaps 

 accounts for its having been observed flying in swarms round a 

 brewery chimney in Essex, in September, 1892. Similarly, Dr. 

 Williston (Canad. Ent., vol. xiv, 18S2, p. 13S) mentions that he has 

 seen " DroHophila ampelopliila, Lw.," in " clouds " about heaps of 

 cider refuse : the same writer remarks that he has never known 

 "perfectly sound fruit" to be attacked by the insects, "but the 

 slightest indication of fermentation attracts them in great numbers." 

 Mr. G. J. Bowles, of Montreal, calls this species " The Pickled Fruit 

 Fly," and gives {ihid., pp. 102-103) an account of its breeding in 

 raspberry vinegar. Under the name of '' The Vine-Loving Pomace- 

 Fly," J. H. Comstock (Report on Insects for the Tear 1881, pp. 6-9, 

 PI. XV: — extract from the Report of the U. S. Department of Agri- 

 culture for the year 1881) describes and figures all stages of the 

 insect, and gives inter alia an especially good figure of the comb on 

 the front tarsi of the male. Dr. Melichar, of Vienna, records (Wien, 

 Ent. Z., XX, Jahrg., 1901, pp. 7-8) the breeding of " Drosophila ampe- 

 lophila, Low," in countless myriads in an open barrel half-full of 



