308 THE MICROSCOPICAL NEWS. 
rain we have had during the past few years, it has rarely been’ 
necessary to add any water whatever, occasionally just a little to 
keep up the level during any warm and dry period we may have 
happened to have, few of which have troubled us for a long time 
past. 
The bottom and sides have a good layer of sandstone rubble 
with a little clay, furnishing innumerable nooks and crevices, where 
plants may root and animals may hide, no attempt whatever being 
made at architectural ornamentation. The rubble, however, is 
carried to and over the edge of the brickwork, which it completely 
hides, and is continued down the outside, making just a bit of 
ordinary garden rock-work, planted in the usual way with ferns, 
saxifrages, etc., forming in summer time a perfect maze of plant life, 
shading the water from some of the sun’s rays, and affording shelter 
for the numerous reptiles which also find a home in or about the 
pond. The whole thing looks like a very humble attempt at imita- 
tion of one of those charming natural ponds one finds among the 
broken rocks on the rugged mountains of North Wales. 
The botanical specimens here grown are very numerous, and were 
selected, I am afraid, on the principle adopted by the man who 
ascertained what were the best remedies for a cold, and then 
endeavoured to take the whole of them. Every plant which 
appeared particularly favourable to microscopic life has been in- 
troduced in some way or other, the result being that the place is 
crowded beyond all need with such plants as Chara, Nitella, 
Anacharis, Myriophyllum, Callitriche, Potamogeton, Lemna, etc., 
while the sides near the water are clothed with Caltha, Iris, Carex, 
and several mosses. 
Besides the above there is a plentiful stock of a plant which has 
proved one of the most fruitful sources of some of the thecated 
rotifers. It is a grass which, my botanical friends inform me, is 
Poa fiuitans, and wherever this is found growing in fairly deep water 
by the pond-hunter, I advise him to pull up some and carefully 
examine the innumerable small fibres which form its roots. 
This plant seems to serve the tube-dwelling rotifers, as the rein- 
deer does the Laplander, or the palm-tree the Asiatic or African, 
for it appears to find both food and clothing in abundance, and I 
have little doubt that the presence of the rare rotifers before-named 
is due to this cause. One of my first finds among its roots was a 
Floscule, of extraordinary size and beauty. I think I exhibited 
some at our meetings having a length of over an eighth of an inch, 
and a Melicerta, if not an unrecorded variety, at least presenting 
many differences from the well-known JZelicer/a ringens ; and, lastly, 
the two already-named rarities Gcistes umbella and Tubicolaria 
maias. 
Of course, the convervoid algz grow much too fast in summer, 
