96 THE BREEDING HABITS OF MUSCA DOMESTICA 



flies caught in restaurants in December. Griffith (1908) has 

 succeeded in rearing M. domestica from eggs in November, 

 December and January under artificial conditions as regards 

 temperature. Jepson (1909) caught flies in January in a 

 Cambridge bakehouse and, under artificial conditions, namely, 

 in a greenhouse in the laboratory with a temperature varying 

 from 65° F. in the morning to 75° F. in the evening, he was 

 able to rear the flies successfully, the whole life-history lasting 

 about three weeks. Gleichen {t.c.) mentions the fact that he 

 obtained eggs in January. 



Hermes (1911) states that at Berkeley in California he has: 

 seen house-flies emerging from their breeding places during every 

 month of the winter season. In early March a veritable plague 

 of flies was encountered while on a trip through the Imperial 

 Valley in California. In sub-tropical and tropical climates the 

 breeding season is continuous thrcjughout the year. 



Abundance of Flies in relation to Breeding Places. 



To anyone who studies the breeding places and habits of the 

 house-fly one of the most striking facts is the enormous number 

 of flies which are able to develop in a certain quantity of breeding 

 material such as horse-manure or excrement. Some interesting 

 observations have been made by observers in different countries 

 on this point. 



Faichne (1909) records experiments carried out in India in 

 which he reared about 4000 flies from one-sixth of a cubic foot 

 of ground from a latrine and as many as 500 from a single 

 dropping of human excreta. 



Herms (1909) in California took samples from a pile of 

 manure after an exposure of four days. The larvae in these 

 samples were counted with the following results: the first 

 sample, 4 lbs., contained 6873 larvae ; second sample, 4 lbs., con- 

 tained 1142 larvae; third sample, 4 lbs., contained 1585 larvae; 

 fourth sample, 3 lbs., contained 682 larvae; the total (juantity 

 examined, comprising 15 lbs, contained, therefore, 10,282 larvae. 

 All these larvae were nearly or quite full-gro\\Ti, and the average 

 number per pound of manure was 685 larvae. The weight of the 



