i6 SCIENCE PROGRESS 



water in use by the villagers. Let the algae, weeds, and mud 

 at the lower end of the village be examined, and they will 

 be found to contain myriads of Pachydrilids. They are here 

 at all times of the year, but at certain seasons are accompanied 

 by Naidids,Tubificids, and other annelids, the genus Lumbri- 

 cillus, however, being invariably the predominant form. 



It must further be observed that it is quite impossible in 

 many such instances to distinguish the fresh-water forms 

 from those which occur among algae on the shore. On the 

 other hand the many inland habitats do undoubtedly supply 

 us with species which would not live in the ooze of estuaries 

 where the water is brackish, or on decaying matter which is 

 impregnated with salt water. The point to be noted is that 

 these red-blooded annelids abound alike in the black ooze of 

 estuaries, rivers, streams, and ponds, and among the decaying 

 forms of vegetable and animal life which are frequently so 

 abundant in sluggish waters and backwashes. 



Denizens of Sewage Works. — Turning our attention to the 

 sewage works and farms established in various parts of the 

 country we shall find that here also they are thriving vigor- 

 ously. They choose the localities for which they are best 

 adapted, or where their work can be most successfully carried 

 out. I have personally inspected such works, farms, or 

 effluents in places as widely apart as Battle and Hastings in 

 the South, Worcester and Nottingham in the Midlands, and 

 Carlisle in the North — to mention but a few — and have at 

 various times received samples from Manchester, Birmingham, 

 and elsewhere. In all these instances such species as L. 

 lineatus, verrucosus, and subterraneus have been found, together 

 with forms which are not so widely known. Welch (12) has 

 shown that L. rutilus is an important agent under similar 

 conditions in certain parts of America. And here one may 

 be allowed to draw attention to the fact that while hardly 

 any thought has been given to this subject under official 

 direction in England — my own researches having been entirely 

 voluntary and unremunerated — in America Lederer(3), Hering, 

 Welch and others have shown the way to the carrying out of 

 systematic and valuable investigations. At the same time it 

 is but fair to mention that the Rivers Board of the West Riding 

 of Yorkshire has recently been issuing some Reports on the 

 Organisms found in Sewage Filters. These are at present 



