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 
Sphaguuin and other aquatic mosses, and the often 
unattractive and slimy-looking alge 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, Sphagiuum, 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 Sphaguum, 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 Anacharis 
or Callitriche 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 Arce//a and Centropyris, and with 
Actinosphertn or other Heliozoa. A peculiarity of the 
