[ 118 ] 



The plots were under continuous observation till the end of June, during 

 which time no difierence was observed in the growth of the different 

 varieties. At this date the plots were searched and only a few larvae 

 could be found. The local observer states that he is confident birds 

 did not interfere with the plots, and the only conclusion that can be 

 drawn is that the larvae migrated from the plots before the crop had 

 germinated. Had they remained and continued their development, 

 pupae and empty pupal cases would have been found in the plots. 

 As a matter of fact these were examined before adult flies had begun to 

 appear. Had the larvae died within the plots it is certain that the 

 remains of some at least would have been found, when the soil was 

 passed through the sieve. But nothing of the kind was found. 



The question remains — do they migrate in appreciable numbers 

 normally, in search of food? On the fields under observation I have 

 found them wandering upon the surface, but so far only occasionally. 

 With regard to the plots, it is to be borne in mind that the larvae had 

 been placed in excessive numbers on soil which did not contain any 

 growing plants (except the ungerminated corn), while around there was 

 abundant green vegetation. Their power to climb up even a few 

 inches of a vertical board was not expected ; that they did so was also 

 evidenced by their being found in the control plots in which none had 

 been placed. 



A further interesting case, bearing on the point, is recorded in an 

 editorial note in the Scottish Naturalist, 1915, p. 1. 



The reference is brief and may be quoted in full: 



"A few weeks ago it was reported to us that the inhabitants of a 

 certain district in Perthshire had been seriously alarmed by an invasion 

 — not of Germans — but of an immense number of small worm-like 

 creatures which crawled over the road near the houses in such numbers 

 as to make walking decidedly unpleasant. Examples of the creatures 

 were brought to us, and were recognised as 'leather jackets' — other- 

 wise the larvae of Tipula oleracea, the commonest species of crane fly." 



As bearing further on this subject, the Editorial note proceeds to 

 quote from an article by P. Desol, in Compt. Rend. Soc. Biol., Paris, 

 Lxxvii. No. 21, June, 1914, pp. 126—7. 



The summary given is quoted from the October 1914 issue of the 

 Review of Applied Entomology (Series A). As the conclusions here are at 

 variance with my own on T. paludosa and with the occurrences just 

 described they are reproduced. The observations were made in the 

 meadows of Avesnois. " In the spring of 1914, circular patches of from 15 



