78 PROCEEDINGS OF THE ROYAL SOCIETY OF Ql'EENSLAND. 



to reach maturity, the time being reckoned as from the date 

 when copulation was observed to occur, as this no doubt 

 takes place soon after the flies are mature. The determination 

 of the length of adult life of the various flies, as recorded in 

 this paper, is not very satisfactory since the insects had 

 necessarily to be kept in confinement from the time of their 

 emergence. Food, temperature, moisture, etc., all influence 

 this period. 



There are unfortunately numerous blanks in the tables 

 given in this paper, some of them owing to the fact that a 

 number of the flies would not copulate in captivity, though 

 they were fljring about in a large room with abundant bright 

 and shady places in it. During the summer it was found 

 possible to carry out monthly observations, but this could 

 not be done in the \Adnter, owing to the difficulty of obtaining 

 suitable species when needed. As the length of the various 

 periods in the case of Lucilia was ascertained to be fairly 

 constant during the several winter months, it has been con- 

 sidered sufficient in most cases to record observations during 

 the winter period (May to September) without specifying any 

 particular months. 



A curious fact noted was that while all the species of 

 carrion-flies could be obtained during any month yet many 

 species had a period during which they gradually increased 

 in numbers relatively and eventually predominated over the 

 other species. 



The observations to be referred to, unless otherwi cd 

 stated, were carried out in Brisbane from the beginning of 

 September 1920 till the end of August 1921, i.e. a full year. 

 Some observations made by Miss Bancroft in Eidsvold (Upper 

 Burnett River) and in Brisbane during 1919 and early in 1920, 

 in connection Avith work carried out in collaboration with the 

 senior author, are included. Certain data presented in this 

 paper were briefly referred to in an article by one of us last 

 year (Johnston 1921). 



Froggatt and Froggatt (1916, p. 9) have published a 

 statement regarding the average number of eggs found in 

 the ovaries of various blowflies in New South Wales. The 

 larval stages of some of the flies referred to in this paper have 

 been described recently by Sinton (1921), while short accounts 

 were published some years ago by Messrs. W. W. and J. L. 

 Froggatt. The dipterous larvae which produce myiasis in man 

 and domesticated animals have been reviewed by Patton (1921). 



