86 THE ROTIFERA 



ill clean ponds round about London, and Mr. Hood has met with it in the Perthshire 

 lochs. 



The NotommatadcB and Philodijuulce have a very wide range. The algs of ponds 

 always hold many species, and many hainit the sediment that Ues on the mud of the 

 bottom. Some of the latter are to be found in gutters of houses, in water-butts, on the 

 blades of wet grass, anywhere indeed where dust can fall and moisture can follow. For the 

 eggs of the llotifera are blown away by the wind from dricd-up puddles, and are scattered 

 broadcast through the air ; and some of the creatures they give birth to can exist appa- 

 rently under almost any kind of moist conditions. 



The AsplanchnadiB fortunately are as indifferent to their quarters as they are large 

 and handsome. I have found them in roadside ditches thickly covered with Lcmna, in 

 farmyard ponds, in the clear water of a miniature lake, and in a foul yellow-gi-een duck 

 puddle in which the fluid (it could not be called water) was so thick that it had to be diluted 

 with five or six times its own bulk, before anything could be seen in it. An Asjilanchna is 

 the very beau-ideal of a Eotiferon for a beginner. It is very large and transparent ; it swims 

 slowly ; and it generally occurs in great numbers. ■ Moreover, its male is even more 

 transparent than the female ; a mere living bubble, thinner and clearer than the finest 

 blown glass. Unhappily, they are as capricious as they are charming; for a pool may be 

 full of them to-day and deserted to-morrow ; and, so far as my own experience goes, they 

 do not occur in the same spot year after year as many Eotifera do. 



The Pterodinadm and Euchlanidce are dwellers in clear ponds, and rather sohtary 

 in their habits. On a warm sunny day the latter may be captured by skunmiug off the 

 Lemnce, and floating bits of leaves and stems, that are driven to the leeward corner of a 

 pool. If the bottle be then allowed to stand a few minutes till the water is clear, a 

 Eiichlanis will often be found slowly gliding up the glass with its long toes pressed 

 against it. It is always worth while to capture it at once with a pipette, and put it uito 

 a small tube along with any others of the same kind, as a hve Euclilanis, properly ex- 

 hibited under dark-field illumination, is one of the choicest treats that the Eotifera afl'ord. 



The PterodinadcB are almost always creeping about the alg;B on the sides of the pond. 

 I never but once have seen any other than solitary specimens, but that exception was a 

 notable one. I then found swarms of them in the small space in which the sluice gate of a 

 pond worked. It was not more than a foot square by about four feet deep, and was mantled 

 over by duckweed. Out of this unlikely spot they were dipped by hundreds, while not 

 one could be found in the pond itself. Of course the duckweed came up with the Ptero- 

 dincB, though as little as possible was taken, on account of the disagreeable way in which 

 it clings to every pipette put into the bottle. On this occasion,' however, I found it of 

 great service ; for, on inspecting the catch at home with a hand-lens, I noticed that 

 the Eotifera wore attached in clusters to some of the roots of the duckweed. Watch- 

 ing for a favourable opportmiity, I whipped one of the Levuia out of the water 

 so suddenly, that the creatures had not time to let go their hold. Then cutting off' the 

 green head, I coiled the stem into a circle on a glass slip, and covered it with thin glass. 

 It was impossible to conceive a moi'e beautiful sight than this natural cage now afforded 

 me. Thirty or forty shields of living glass were Hashing across the field of view hi every 

 direction ; some were adhering to the stem, swaying backwards and forwards so as to 

 present themselves in every point of view, while others were moored to the glass cover, 

 thus giving an admirable opportunity of making out their structure. 



It was a memorable occasion, but I never had such a chance again. 



I have yet to speak of the Synchcetada among the free-swimmers. Both the genera 

 included in this family are to be found in open water ; and both alike shun dirty ponds ; 

 though in different degrees, for Synchata is absolutely intolerant of them ; while I have 

 dipped up Polijarthra from the hollows of a muddy bottom where once a pond had 

 been. 



Both genera are tolerably common, and ai'e often to be caught in considerable 

 numbers. The habits of the two chief species of Synchata, viz. S. viordax and S. 



