490 TEOCEEDINGS OF THE THIRD ENTOMOLOGICAL MEETING 



included is less tlian 2 per cent. The damaged bolls and the sound bolls 

 together make up the entire yield of all the plants from which they were 

 taken. 



It will be seen that the only set of samples needing control and for 

 whose sampling no check can be found consists of the damaged seeds 

 other than double ones. 



The following conclusions appear to be justifiable on comparing the 

 percentages of lint of all the samples together before removal of the 

 worms. 



The 30 sets of sound seeds approach very closely in their percentage 

 lint to that found for the entire crop, the difference being only 0"2 per 

 cent. ; the closeness of results, in view of the small size of the sample, 

 •may in part be due to chance. 



The 30 sets of random samples are also not very far out in percent- 

 age lint, being 0-7 per cent, in excess. 



The " damaged " seeds and the " double " seeds vary most from 

 the normal, as was to be expected, but it is almost surprising that they 

 varied so little. The " damaged " seeds are only 1-5 per cent, above 

 the normal. Remembering that the sound seeds varied to half this 

 extent from the normal and the entire bulk of the 30 samples was 

 in itself small, it is questionable how much significance should be 

 attributed to the figures. On the other hand the " double " seeds are 

 3-75 per cent, below the normal. In their case part at least of the 

 difference may be real, especially as a certain amount of the lint on 

 both components is probably destroyed by the worm when attacking 

 the seeds together. Hitherto, we have been reckoning the weight of 

 the worms in with the seed weight, as would happen at a ginnery when 

 calculating ginning outturn. Obviously- the weight of the worm com- 

 pensates to a large extent for the lost seed weight in the percentage 

 lint calculations. However, on comparing the total weights produced 

 by damaged seeds and double seeds with that of the sound seeds, it is 

 very obvious that a considerable loss of substance has occurred, which 

 strangely enough is distributed in such a manner that lint and seed 

 plus worm are in very nearly the same proportions as lint and seed in 

 normal seeds. Removing the larvae from these samples, the percent- 

 age lint rises two to three per cent. 



The '■ Gemmaiza crop " samples are much bigger individually and 

 together than the sets just under consideration. Here, as was normal, 

 the component samples varied in percentage lint, the standard devia- 

 tion being approximately 0-5 per cent. The entire samples on the 

 other hand all worked out to 34 per cent, lint (seed weighed including 

 worms). 



