13 



feet long had been tied over the mouth of the discharge pipe in the 

 car standing on the sidetrack. In this particular instance the fan was 

 of 'M-inch size and was run at 1,800 revolutions per minute. A care- 

 ful examination was made of the contents of the bag, but it was found 

 that no weevils passed through alive. The weevils were cut into small 

 fragments bj^- the swiftly revolving blades of the fan. 



A second experiment was designed to determine whether weevils 

 might pass through the gin itself when in actual operation. One hun- 

 dred and fifty marked live weevils were fed directly into the outer roll 

 of an 80-saw gin, revolving at the rate of 400 revolutions per minute. 

 The first seed, run through in about one minute, was collected and 

 examined separately. Then the whole roll was thrown out after about 

 two minutes. The mote dust was also collected and examined. The 

 Heed run out during the first minute yielded 47 marked weevils alive 

 and 3 marked weevils dead. The main bulk of the roll contained about 

 15 times as much seed as collected in the way just described. It yielded 

 40 marked weevils alive and 5 marked weevils dead. The mote collec- 

 tion yielded 10 marked weevils alive and no marked weevils dead. The 

 total number of marked weevils collected in this experiment was 105; 

 the percentage of marked weevils recovered was 70; the percentage of 

 recovered marked weevils alive, 92.4, and the percentage of recovered 

 marked weevils dead, 7.6. A number of unmarked weevils which had 

 evidently passed through the pneumatic feeder to the gin breast were 

 found in the course of this experiment. They are, of course, omitted 

 in the above figures. 



This experiment, which was repeated at different times, demonstrated 

 that in actual ginning weevils escape from the gin at two points, one 

 with the seed into the seed chute and the other with the motes at the 

 mote board. 



The following experiments demonstrated the fact that in addition to 

 the two avenues of escape that have been mentioned weevils also pass 

 through cleaning feeders, in many cases without being injured. A lot 

 of 200 live weevils, marked as above described, was run through a 

 modern cleaner feeder, consisting of fluted rollers, picker roller, and 

 the accompanying screens. In this case the picker roller was run at 

 about 170 revolutions per minute. The weevils were fed into the top of 

 the cleaner feeder at the point where the cotton becomes dead. The 

 trash from the spiral conveyor tube was collected for about ten minutes, 

 as was also the seed discharged by the gin during that time, in addition 

 to the motes. Results: Marked weevils extracted by cleaner feeder, 

 alive 54, dead 7, total 61 ; in the seed thrown out, marked weevils alive 

 6, dead 5; among the motes, marked weevils alive 9, dead 5; total 

 marked weevils found, 86, or 43 per cent of those put in. As in the 

 preceding experiment a number of unmarked weevils were found. 



209 



