Olf THE FOOD OF UROPODA. 623 



On the Food of Uropoda. 

 By Surg.-Capt. H. A. CirMMiNS, M.D., F.L.S. 



[Bead 2nd June, 1898.] 



"When examining diseased bulbs of the Easter lily (Lilhtm 

 longiflorum, var. Harrisii), which is largely grown in Bermuda, 

 I found them infested by several species of mite. 



One o£ these, Vropoda ovalis, Koch, was present in large 

 numbers, and multiplied very freely when kept under favourable 

 conditions in captivity. 



This circumstance allowed me a good opportunity of observing 

 what constituted the food of these creatures, which I believe has 

 not hitherto been proved with certainty. 



As to my method of investigation and apparatus, I found 

 that rectangular or round glass boxes 2 or 3 inches in diameter, 

 provided with covers as used in bacteriological work, were best 

 suited to the requirements of the case. In the bottom of each 

 box was placed a small piece of moistened filter-paper, and on 

 the filter-paper a lily-scale or small portion of potato. Finally, 

 the lid was sealed after the mites had been introduced. 



The supply of air in the box was sufficient to last for several 

 days, but as it was my custom to examine each box daily, there 

 was no danger to be apprehended from suffocation, as the Jid 

 was removed. 



My attention was drawn to the way in which the mites 

 obtained their food. As they walked too and fro on the lily-scale 

 or potato, the mandibles were rapidly protruded and withdrawn. 

 This was particularly the case at spots on the potato where 

 colonies of bacteria were growing. If, for instance, a mite were 

 removed from a box where it had been living on a lily-scale, and 

 were placed in another which contained potato slimy with 

 bacterial colonies, it fed at first with avidity, but apparently 

 soon became filled to repletion, as the protrusion of the mandibles 

 ceased. 



The following is an extract from my notes, and relates to a 

 box which I frequently used for expeinmeats : — 



