li- 

 the first column the black line reach e nd in the second 47"C. 

 fn the third the ex;ict |>oint when- it -hould terminate is doubtful, 

 owing to the fewness of the figures, but it must be betu< and 

 47 C. Coni])letc mortality at 47 ('. with ;i,nd a half mini 

 treatment is rather astonishing at first sight, since it is a better result 

 than was obtained with live minutes' complete immersion in hot \v 

 The explanation of this lies in the fact that the band travels very slowly 

 and that the temperature in the middle of the hot-air chamb> 

 much higher than that at the ends, with -alt that during 

 final stages of its jotirnev through the machine' the s< >rohably 

 falling in temperature, while at the end of its journey it is exposed 

 for a short time to the temperature of the outer air before reaching 

 the collector, so that the recorded temperature is not th mm 

 temperature actually reached by the seed. This view is supported by 

 the figures for the germination of the seed given in Table. II. from 

 which it will be seen that at the slov. ds in this D the 

 seed is badlv damaged at impossibly lov A further 

 confirmation of this explanation lies in the fact that a maximum 

 thermometer, passed through the machine on the band at a 

 when the temperature -eated seed was only .")(! ( 

 maximum reading of over IO(i"C. 



In the Ministry's hot-air machine, likewise .'ibtedly 



is cooled down considerably from its maximum tempera.tuiv 

 being delivered into the sack, most of this cooling probably taking 

 place in the screw conveyor which withdraws the 

 bottom of the machine. The conveyor is made of thin i; 

 iron and exposes" a considerable surface to the air. and as tl 

 travels along it quite slowly it has considerable opportunities for 

 losing some of its heat. Consequently tip with it 



speeds- -given in the sixth, seventh, and eighth columns agree 

 closely with the results obtained in the Domains' machine. 



The la,st three columns give the results of a, large number of 

 experiments with Simon's machine. The first of them gives the I inures 

 obtained from seed that had been sacked hot. the sampl. 

 ta,ke.n more than an hour after the seed had left the machine. ! 

 it will be seen that the mortality of the worms is verv nearly com). 

 at 51" ''. a.nd is absolutely complete from .~>IJ" ('. upwards. In the 

 second of the three columns are given the result number of 



