184 POND-HUNTING IN WINTER. 



length, but most sincerely wish that our (so-called) practical 

 microscopists would follow his advice more fully. 



Those microscopists who keep an aquarium, and are in the 

 habit of searching in it for living microscopic animals, must have 

 noticed that when there is a superabundance of decaying vegetable 

 matter in the aquarium, — that is, when there is only so much decay 

 taking place in the water as will not interfere with the health of 

 the higher animals inhabiting it, — the microscopic animals are 

 found in the greatest abundance. The Polyzoa and Tubular 

 Rotifera, especially, are found to be in the best condition under 

 these circumstances. 



The winds of October and November drive a large quantity of 

 dead leaves and other lifeless vegetable-matter into the ponds, 

 which decaying, form a black offensive ooze. This is generally 

 to be found congregated in the shallowest part of the pond, 

 covered only by a few inches of water. 



In this ooze, the prevailing forms of animal life will probably 

 be — Chilomo7ias and AmcEba^ in great abundance, Trachelocerca 

 olof'i Euglena de?tses, and JE. pyrimi. 



These may generally be found in this part of the pond, in a 

 very fine and healthy condition. If the pond is of moderate size, 

 some portions of the water will be found quite " sweet," and yet 

 containing a large amount of the " lower forms," especially if they 

 are partially shaded from the light; we may look for Limnias 

 ceratophylli^ Stephanoceros Eichornii, Floscnlaria ornafa, Melicerta 

 7'inge?is, and various other " hard-feeding " Rotifers. (We enu- 

 merate these because they are so popular, and well-known to 

 every microscopist). 



Sometimes in ponds, but more generally in rivers, canals, or 

 ditches, we find large quantities of the " American Water-Weed," 

 " Anacharis Alsi7iastniin,'' which in the summer-time almost 

 chokes them. In the winter the greater part of this plant dies 

 down, forming a light-brown deposit on the surface of the mud. 

 If the old stems are examined, a host of interesting specimens 

 will be obtained. 



The following will show our success on one occasion : — 



"Nov. t8, '8 1. — Meanwood arches, took in quantity : — P/iilo- 

 dina roseola and B?'achio7iis pala; Mastigocerca carinata, Polyart/ira 

 platypiera^ Actmums Nepttmms, Stcntor Jitger, and S. Mullcri ; 

 ActiiwpJuys sol ; Trachelius ovujn, Coleps /lirtus, Tai'digrada'' 



The above is extracted from some notes of 1881. The organ- 

 isms were obtained from one ditch, in four gatherings, as shown. 



The Alg?eologist finds a rich reward for his trouble in search- 

 ing the mountain-streams, and moorland tarns and ponds in 

 winter, — perhaps at no time in the year is there so rich a harvest 



