C. H. Martin Aind K. R. Lkwin 111 



In the rather coarse, sandy soils, at Abergavenny, fair results 

 were obtained in the case of small flagellates, thecamoebae, and small 

 amoebae, by allowing a stream of water to flow from the tap on to a 

 quantity of the soil in the dish, until the soil was just covered, and 

 then examining the surface films collected as above. 



In the case of rather dry, clayey soils at Rothamsted, fairly large 

 amoebae, with a thick pellicle, were obtained by the bubbling process 

 described below. 



A glass tube of internal diameter 1 J" and length about 2' is provided 

 with a singly-bored rubber cork at the lower end. Through this passes 

 a glass tube drawn out to a jet. Connection is made with some form 

 of airblast, so that a stream of air can be blown through the jet. The 

 tube is clamped upright and a newly made suspension in water of the 

 soil to be examined is poured in until the water level nearly reaches 

 the top. Three hooks (conveniently made of bent strips of "tin"') are 

 hung round the rim of the tube in such a way as to furnish a support 

 for the coverslip. The coverslip is placed in position about I" above 

 the water level. Air is now blown through the jet so as to produce 

 a stream of fairly small bubbles rising through the suspension and 

 breaking on the lower surface of the coverslip. The water level can be 

 adjusted within small limits by regulating the air-flow. 



■ After about 30 seconds the air-stream is stopped, and the coverslip 

 lifted off and examined under the microscope. It is frequently of 

 advantage to place a thin sheet of agar jelly on the lower side of the 

 slip before commencing the bubbling, as the protozoa adhere more 

 readily to this substance than to the glass. If this be done, the cover- 

 slip is placed for examination, agar side up, on a slide, and another 

 slip is dropped on to the agar surface. 



By this method there were obtained from a Rothamsted soil certain 

 amoebae whose presence in the active fauna the other methods had 

 failed to reveal. 



Very fair stained preparations of any of the animals obtained by 

 one of the above methods can be made by the ordinary processes 

 in use in the zoological laboratories for making preparations under a 

 coversUp. The easiest method is probably to fix by running a drop of 

 Fleming's solution under the coverslip for a few seconds, then washing 

 through with water, followed by picro-carmine five to ten minutes 

 (this renders the process of staining after the Fleming fixation much 

 easier), washing through again with water, staining with alum carmine 

 for half an hour, washing through again with water, then alcohol up to 



