32 BRITISH FRESHWATER RHIZOPODA. 



but in the latter situation not in large colonies half-a- 

 dozen individuals together being the maximum number. 

 Usually they occur as single individuals or in pairs, or 

 in small colonies of four or six. 



COLLECTING. 



For the reception of pond-gatherings, squeezings of 

 Sphagnum and other aquatic mosses, and the often 

 unattractive and slimy-looking alga3 found growing on 

 dripping rocks, the collector of Rhizopoda should be 

 furnished with a number of wide-mouthed bottles or 

 test-tubes, the latter preferably, as the thinness and 

 clearness of the glass admits of inspection in the field 

 with a high-power lens. 



A vasculum is the most convenient receptacle for 

 tufts of wet moss, Sphagnum, etc., from bogs and pond- 

 sides. It is desirable to make a note of the localities 

 from which these are taken, in order that the habitat 

 of any rare species which may turn up during micro- 

 scopical examination may be noted. Provided it be 

 kept moist, and in a growing state, the Sphagnum, etc., 

 with the Rhizopodous life which it harbours, may be 

 preserved for weeks or months, affording material for 

 constant study, It is desirable to bear this in mind 

 when a summer excursion to Wales or Scotland is 

 contemplated. A gathering of Sphagnum can be kept 

 perfectly fresh through the winter in a garden-frame. 



Water, in small bottles, is apt to get foul unless 

 some growing vegetation be kept in it. At the same 

 time, if from a locality rich in Rhizopoda, it would be 

 unwise to throw it away too soon. A stem of Anacharix 

 or CaUitriche introduced into a two- or three-ounce 

 bottle of water, at the time of gathering, will keep it 

 sweet and healthy for many weeks. In a short time 

 the side of the tube nearest to the light will become 

 crowded with Rhizopod life, especially with such tes- 

 taceous forms as Arcellse and Centropyxis, and with 

 Actinospherinm or other Heliozoa. A peculiarity of the 



