240 mr. a. m. altson on the life-history and 



Refrigerating Experiment, 



111 order to ascertain if the parasites would be able to undergo 

 six weeks— the length of sea voyage to Melbourne — in the re- 

 frigerator of a ship, a few of the para,sites etc. were given a test. 



Prof. Blackman was approached, and kindly gave the writer 

 permission to use a small cupboard in a refrigerating machine in 

 his department. 



Text-fiffure 20. 



Mandibles of Nasonia hrevicornis male: (a) left; (b) right; (c) right, in profile, 

 outer tooth on top. X 160. Original, (d) Mandible of female MelUtohia 

 acasta ; onlj^ females of this species emerge. After Waterston. (d) is not 

 proportionate with (a), (b), and (c). 



As other experiments were going on at the time, it was necessary 

 to use a burying medium in which no insect life existed, and 

 clean sand was therefore used. 



A laro^e glass jar was used as the receptacle, and sand to a 

 depth of o' inches was run into it as a foundation. A few 

 puparia containing A. manclucator, N. hrevicornis, Calli'phora 

 erythrocejjiuda, and a few larvse of the latter species were each 

 buried in sand in separate glass tubes left open ; these were then 

 pushed into the 3-inch foundation of sand to keep them vertical. 



The jar and contents were put into the chamber on 28th 

 ISTovember. The constant temperature was reputed to be 2° C. 

 On 15th January — 6 weeks and 6 days later — the jar was 

 removed to the laboratory and the contents examined. 



One Braconid, a male, had emerged, on what date is unknown; 



