Sibyl T. Jewson and F. Tattersfield 



221 



The eggs are obviously much more resistant than the mites them- 

 selves and it is apparent from the discrepancy between Series I and II 

 that a sUght change in the conditions of carrying out the experiment 

 may lead to failure. In view of this a fresh series of experiments (III) 

 was set up, the results being shown in Table IV 6, which also gives the 

 action of Ammonia vapour on the eggs. 



Table IV 6. 

 Series III, Effect of Pyridine and Ammonia on Eggs of Cheese-mites. 



Temp, of exposure 18°-19° C. 



Exposure in flasks sealed with lead-lined stoppers. 



Air of flask saturated with vapour. 



Time elapsing before examination is reckoned from time of taking out of flasks. 



Pyridine. 



