'? 



26tb. 



October 



1st. 



)? 



4th. 



55 



8th. 



55 



11th. 



55 



13th. 



55 



25tb. 



No-veniber 



2nd. 



624 SUEG.-CAPT. H. A. CUMMINS OK 



September 16tb, 1897. Introduced about eight JJro- 

 poda on a lily-scale into the box. 

 „ 19th. A few young mites appeared. 



Presh young. 

 Grreat increase in number. 

 Further increase. 

 Quite innumerable. 

 Ditto. 

 Ditto. 

 Introduced a piece of potato. 

 Mites swarming on potato. 



In bright daylight the mites usually sought the under surface 

 of the potato, a few walking on the upper surface, but in the 

 evening time they left their hiding-places and wandered over the 

 interior of the box and on the potato. 



In this box the slimy colonies of bacteria or wild yeasfc were 

 absent, and the conditions were well adapted to the experiments, 

 which T carried out in the following manner : — 



I scraped some of the slimy masses from a piece of potato 

 which had been specially kept for the purpose. These were 

 placed under a microscope, and when I had satisfied myself 

 that they were composed of micro-organisms, I placed them on 

 the potato in the box, before mentioned, containing mites. 



In about half a minute one or two mites would discover the 

 bacterial matter, but soon numbers would collect, scrambling 

 Avith each other for the food. At this time the mandibles could 

 be seen, with the aid of the microscope, working with great 

 rapidity. In five or ten minutes nothing would be left of the 

 substance I had introduced. The Uropoda appear to have the 

 faculty of detecting the presence of food matter situated some 

 distance from them, for soon after its introduction they swarmed 

 almost direct to it from all sides. They certainly did not dis- 

 cover the food by chance. 



I tried this experiment several times, and always with the 

 same result. 



Amongst the organisms which the JJropoda consumed were 

 the following :-^ 



Many species of bacilli, which I could not identify with 

 certainty, but I believe that I detected the ordinary potato 



