FOOD 239 



insects by aeroplanes is scarcely any longer an entirely novel 

 subject. The possibility, for example, of mosquitoes infected 

 with the virus of yellow fever becoming stowaways in aeroplanes 

 and thus obtaining passages to territory free from that disease 

 is a subject of inquiry at the present time. In England an 

 investigation of insects of the upper air is being carried out under 

 the direction of Professor A. C. Hardy of University College, Hull. 

 By the use of suitable kites, with opening and closing nets attached, 

 the heights at which insects are obtained can be properly registered. 

 This method is an adaptation of the tow-net principle used in 

 sampling life in the depths of the sea. Professor Hardy informs 

 me that, so far, rather more than 2,000 feet is the maximum height 

 sampled. A series of nets, attached at different heights, to the 

 300 feet masts of a wireless station in Lincolnshire is another 

 experiment. It is providing information respecting the drift of 

 insects at such heights in relation to meteorological data on a 

 linear distance of approximately one mile. Similarly, by flying 

 kites with nets attached, while on board a fisheries research 

 vessel in the North Sea, Professor Hardy states that quite sur- 

 prising collections were obtained of insects drifting above the sea 

 up to a distance of 150 miles from the land. In these cases the 

 kites were flown up to 400 feet in the air, while other nets were 

 attached to the masthead of the vessel. The preparation of some 

 of the results of this work is now nearing completion for the i3ress. 



Food 

 The General Subject. In dealing with the influence exercised 

 by food we arrive at the point where physical and biological 

 factors intergrade. A large amount of scattered and unco- 

 ordinated information exists with regard to the role of food and 

 its constituents upon insect life, and an annotated bibliography 

 of the subject, including nearly 600 titles, has been compiled by 

 Uvarov (1928). Much of this information belongs to the realm 

 of pure physiology, and a considerable proportion of it requires 

 revision in the light of improved methods of technique. From 

 the ecological standpoint, the effects of nutriment upon growth 

 and reproduction are fundamental, but the subject cannot be 



