500 PKOCEEDINGS OF THE TIIIKD ENTOMOLOGICAL MEETING 



bearing a number of broad propeller blades which force the seed from 

 one end to the other. 



A sample of seed treated at 55°C. showed complete mortality of 

 the worms, but about 5 per cent, of the seed is damaged in the process. 

 This damage must certainly be due to the overheating of a number 

 of seeds that have remained too long in direct contact with the heating 

 surface. It was observable that masses of seed in front of the propeller 

 blades traversed the lower part of each revolution en masse with very 

 little movement inter se. The outermost seeds of such masses would 

 consequently remain in contact with the surface of the steam-jacket 

 for a considerable period, as the rate of revolution was very slow. 

 Obviousl}^ it should be possible to overcome this defect by keeping 

 the seed in more rapid motion during its passage through the machine. 



Apart from this one remediable defect the machine was very satis- 

 factory. In a trial the first seed that came tlirough had a temperature 

 of 50° C. which rose very gradually and regularly to 55° C. where it 

 remained constant. 



The other machine, known as the Delta, has been approved 

 as complying -svith the requirements of the law, and has been adopted 

 by some of the ginneries. One has been working with very satisfactory 

 results for two seasons at Beni-Suef. It is practically identical in 

 principle with Lenzi's machine, but instead of consisting of a single 

 long cylinder, steam-jacketed all round, it consists of three shorter 

 cylinders, placed one above the other, and steam- jacketed on the lower 

 half only, the upper half being a lid which can be removed so as to 

 facihtate the cleaning of the cyhnders. In each cylinder there is a 

 revolving framework which carries on its circumference a spiral band 

 which propels the seed along the cyhnder, and a number of longitu- 

 dinal bars which keep the seed in constant motion, the whole framework 

 revolving quite rapidly. The seed enters through an automatic feeder 

 at one end of the uppermost cylinder and, after passing through the 

 three cyhnders, is delivered at the other end of the bottom C3dinder. 



In more recent models the machine has been made to consist of a 

 single cylinder equal in length to the three component ones of the earlier 

 pattern. This modification was introduced in order to let the machine 

 fit into the available space in a factory with less alteration to building. 



Although the legislation enforcing seed-treatment was passed in 

 1916, and although ginners were given a clear year in which to supply 

 themselves with the necessary machinery, the law could not be enforced 

 until 1918, because of the difficulties in obtaining machinery in war time. 

 This difficulty was increased by the want of interest on the part of 

 some of the ginners, who postponed ordering their seed-treating machines 



