MR. U. REID ON THE NATURAL HISTORY OF ISOLATED PONDS. ‘It I 
also be observed that the drought of 1887 probably killed a good 
many of the plants, for not only did many of the pools completely 
dry up, but the farmers took the opportunity, in many instances, 
to clean out the mud and deepen the ponds. 
Large dew-pond on the open Down nearly a mile east-south-east 
of Amberley Station ; height 310 feet above the sea, and 300 feet 
above the marshes of the Arim ; nearest water, the marshes of the 
Arun, distant half a mile. Noted 15th November, 1884. This 
pond has evidently been made several years, and is now full of 
water-plants. The species observed were Juiu'us (not in flower 
or fruit, though very abundant), Potamogeton dermis (very 
common), Ranunculus cu/uatihs, Chara, and a single small, but 
vigorous tuft of Elodea canadensis. This was the first time that 
Elodea was observed in an isolated pond,* though I have since 
come across three other cases of its occurrence. As the plant never 
fruits in this country, it probably has been transported twisted 
round the leg of a bird. (I have apparently omitted to note the 
mollusca from this pond, if there were any). 
Kedlion Pond, on the open Down, three miles south-east of 
Lewes ; height 540 feet above the sea, and 530 feet above the 
marshes of the Ouse; nearest water, the marshes of the Ouse, 
distant seven furlongs. Noted June, 1890. The species observed 
were Limniva peregra, Ranunculus ac/uatilis, and Elodea. 
Small pond by the side of the high road half a mile west of 
Christ Church, Stansted (near the Hampshire border) ; height, 
312 feet above the sea, and 220 feet above the nearest stream; 
nearest water, a small stream, distant about two miles to the 
south-south-west, but apparently containing neither of the plants 
found in the pond. Noted September 25th, 1S91. The species 
found were Limmva peregra, Planorbis spirorbis, Potamogeton 
natans , Zannichellia palustns, all abundant ; the two plants in 
fruit, and carrying many eggs of Limncea. Zannichellia occurs 
again in a pond in a brick-field two miles to the south-west, but 
does not fruit there ; the nearest natural station for it seems to be 
in the slightly brackish marshes near Emsworth, four miles to the 
south. Potamogeton natans can probably be found within three 
miles. This pond is overshadowed by a large oak, and supplied 
by dew and rain off the road ; neither of the plants, however, is 
