SYSTEMATIC ACCOUNT. 91 



one in which he described new Diptera appeared in 1865. It seems fairly- 

 safe to conclude that D. melanogaster became common in upper New York 

 State between 1865 and 1875. 



It seems curious that the name melanogaster should have been overlooked 

 by Loew, and should have been neglected by other workers for so long. 

 It was recognized by Schiner in 1864, but seems not to have been used 

 thereafter until Austen (1905, Entom. Mag., p. 276) pointed out that it 

 was an earlier name for the form then known as D. ampelophila Loew. 

 But even then the point was overlooked by most entomologists until redis- 

 covered by Villeneuve (1913, Wien. ent. Zeit., 32, 128). The synonymy of 

 D. nigriventris Zetterstedt was pointed out by Schiner (1864, Fauna Austr., 

 2, 277); that of D. uvarum Rondani by Mik (1883, Verb, zool.-bot. Ges. 

 Wien., 33). Mik was also the first to conclude that the species is cos- 

 mopolitan. 



D. melanogaster is to be found most commonly about houses or grocery 

 stores, or in orchards or fields. It is not a common woods species. It seems 

 to me doubtful if it hibernates in the Northern States. I suspect that the 

 only survivors of the winter have lived indoors when it was cold. New 

 stocks must be continually brought in from the tropics on banana boats, 

 so that the race to be found in any one locality is very likely continually 

 changing, through the introduction of "new blood." The species is pri- 

 marily a fruit eater, though it can be bred on various other substances. 

 Howard has bred it from human excrement, but this is exceptional, as the 

 species is not usually attracted to such material. I have bred it from 

 apple, banana, blackberry, fig, grapefruit, grape, guanabana, huckleberry, 

 mariiion, papaya, peach, pineapple, plantain, potato, tomato, zapote, and 

 stale beer. Banana and peach are the most satisfactory of these for labor- 

 atory purposes. A still more satisfactory method of feeding these flies in 

 the laboratory is the banana-agar method described elsewhere in this 

 paper. 



The eggs have two filaments. Females will sometimes lay eggs when 

 they are only a day old, but mating and oviposition usually begin on about 

 the second or third day. From eight to twelve days are ordinarily required 

 for development, depending on the temperature and food conditions. The 

 chromosomes, mating habits, genetic experiments, and tropisms are de- 

 scribed elsewhere in this paper. 



Drosophila simulans Sturtevant. 1919. Psyche, 26, 153. 



cf, ?. No constant and usable differences from D. melanogaster, except that the 

 cheek (measured just below the lowest point of the eye) is a little broader (c/. figs. 45 and 46), 

 and that the shape of the clasper and of the posterior process of the first genital segment of 

 the male (figs. 13 and 14) are distinct. The shape of the cheek is difficult to be sure of, 

 and the male genitalia can not be examined satisfactorily except in relaxed material. The 

 spermathecse do not differ from those of D. melanogaster. 



Specimens examined: Randolph, New Hampshire (Miss H. Daniels); 

 Cold Spring Harbor (C. W. Metz), Staten Island (F. Schrader), New York; 

 Rochester, Minnesota (L. Huckfield); Richmond, Virginia; Macon, Georgia 

 (G. L. Carver); Lakeland (C. W. Metz, type material). Palm Beach (B. B. 

 Horton), Key Largo (F. Knab), Florida; Kushla, Alabama; Fayette ville, 

 Arkansas (B. Schwartz); Port Limon, Costa Rica; Taboga Island, Panama 

 (A. Busck); Sao Paulo (F. Iglesias), Matto Grosso (Harris), Brazil. 



The mating and breeding habits of this species are almost identical with 

 those of D. melanogaster. The species is almost as common as D. melano- 

 gaster in the neighborhood of New York and in southern Alabama, but has 

 not yet been recognized in material from the Pacific coast, the West Indies, 



