NEAR AMBERLEY. 21 



to watch these queer Httle folk swimming steadily on, and then 

 darting back, but not quite so far as they advanced. They will 

 keep up this peculiarly unrestful motion by the hour together. 

 Increasing by self-division, they multiply so rapidly that it has been 

 calculated that one Stylonichion might produce a million in ten 

 days. Who can gauge the usefulness of all these minute beings, 

 so delicate that a touch will crush them ! and yet so important 

 that without them every stagnant pond would become a centre of 

 infection spreading death to all around. Professor Owen calls 

 them " Nature's invisible Police," and indeed they are Uke 

 watchful sentinels, ever waiting to arrest all the particles of decay- 

 ing matter, to turn them back into the ascending stream of animal 

 life. Thus they prevent the gradual diminution of the quantity of 

 organised matter, taking that which would harm us into their own 

 living tissues, and then becoming the food of larger Infusoria, 

 which in their turn are devoured ; food fit for more highly 

 organised beings coming back by this short route from the extreme 

 limits of the world of organised matter. Wherever decay com- 

 mences, the invisible fairy band of scavengers will be found, and 

 they never, fortunately for us, leave their work unfinished. In 

 their crystal goblets poison changes into food. 



I found Hydra plentiful in the ponds near Stroud ; both H. 

 vulgaris and H. viridis which some naturalists tell us is only a 

 variety of the former. They are very tenacious of life, and I have 

 divided them into many pieces and found each division speedily 

 grow a fresh crown of tentacles. It is known that they have the 

 power of stinging their prey by means of tiny lassoes which they 

 can throw out at will. I had not time to examine the ponds 

 round Amberley, as I should have liked, but from what I saw I 

 should think the ponds, canal, and the Brimscombe basin would 

 repay careful research. 



Those who take an interest in conchology may care to know 

 that in " Hardwicke's Science Gossip " for July, there is mention 

 of a rare slug to be found at Brimscombe. It is the variety 

 Bicolor of Arion ater^ which I believe at present has only been 

 found in Ireland. It is always pleasant to see what sort of free- 

 masonry exists between naturalists ; they seem as a rule very free 

 from the selfishness of some collectors, and can rejoice in each 

 other's prizes. 



