68 THE REPORT OF THE No. 19 



The terrestrial apparatus is made of copper, lined with. tin. It consists 

 of a central cone underneath which heat is applied. Four funnels with 

 smooth tin lining and at the bottom of each is attached a small glass phial 

 which may or may not contain alcohol. The funnels are surrounded by 

 water and the water is kept hot from the gas burner below. On the top of 

 each funnel is placed a shallow or deep tray of metallic network and on 

 them is placed the material to be examined. The water is gradually heated 

 and as the mites become uncomfortably hot they leave their host or other 

 material on which they feed and travel downward into the glass tube below. 

 If the life-history of the mite is desired, they are removed from the bottle 

 and placed on suitable media. If the specimens are to be preserved, the 

 tubes are usually filled with 95 per cent, alcohol or some other suitable 

 preservative. (Figs. 18 and 19.) 



A partial list of materials from which mites have been obtained is as 

 follows : 



Manure : Mites were obtained from nearly all kinds of manure and 

 were especially abundant in horse and cow manure. From one small lot of 

 horse manure the mites dropped down b'ke a snow storm and filled a 4 cc. 

 phial in a few minutes after the water was heated. Five different specie* 

 were taken from this one lot. 



Baric from Trees : The bark from a host of deciduous and evergreen trees 

 were given a trial on the mite machine, and from nearly every species of 

 tree one or more species of Acarid was taken. Many mites resemble the bark 

 in colour or shape, on which they live, and if it were not for such a device 

 it would mean an endless amount of waste in time and patience. A good 

 example of this is that of a species belonging to the genus Nothrus. Thi« 

 mite in shape and colour resembles bits of bark or lichens. 



Ensilage : A large quantity of mites were taken from ensilage from 

 the 0. A. College silo. These acarids may be largely responsible for the 

 spread of fungus spores in the silo. 



Bone : Some mites were taken from pure bone and others from bone 

 with remnants of flesh adhering to it. 



Rock : This is one of the favorite resorts of acarids. Some species evi- 

 dently live on the sound rock, others on the I'chens or decaying organic 

 matter on the rock and still others take refuge in the crevices of rock. Many 

 species were obtained from this source. 



Decaying leaves, humtis, soil from roots of plants, etc. : Decaying 

 leaves is especially a very favourable resort for acarids. Some live on the 

 decaying matter and others hibernate under the leaves. 



Bulbs and Tubers: Here again nearly every kind of bulb and tuber 

 tested yielded one or more species of mite, e.g., Potatoes, Calla Lillies, 

 Hyacinths, Onions, etc. 



Fruits: Only a few fruits were tried. The apple is the only one that 

 responded. The mites on the apples were feeding on the wax covering 

 the surface. The King gave the best results. 



Roots and Vegetables, etc. : From beets, mangolds, turnips, arti- 

 chokes, Kohl Rabi, parsnips, squash, mites were obtained. 



In root houses and such places the mites carry spores of moulds on 

 their feet and disseminate the fungus. 



Moss ; A few species were obtained from moss. 



