X POTAMOGETON FLUITANS IN HUNTINGDONSHIRE. 355 



remarks on interesting species of Physarum and Dklymium found in 

 great abundance in these localities, and exhibitiug unusual characters. 

 It would be well if those who are interested in these organisms would 

 investigate such straw heaps during the summer and autumn, 



X POTAMOGETON FLUITANS IN HUNTINGDONSHIEE. 

 By Alfeed Fryer. 



Shortly after the discovery of P. fluitans''- in a small pit by the 

 side of the forty-foot , or Vermuyden's Drain, in Ramsey parish, 

 the pit was used as a receptacle for rubbish from a neighbouring 

 cottage. Foreseeing thence the probability of the plant soon 

 becoming destroyed in its sole locality in Huntingdonshire, I 

 planted some roots in a recently-dug pit near Warboys Wood. 

 Although the subsoil of the pit was Oxford Clay like that of the 

 Ramsey locality, the plants did not thrive for some years, probably 

 from the want of the decayed vegetable mud which forms the lower 

 stratum of the woody ponds in which Potamogetons flourish. 

 Time, however, remedied this defect, and two years ago I saw that 

 the roots began to spread a little about the pond. 



In July of the present year I again visited the Warboys locality, 

 and to my delight found a mass of P. fluitans extending over some 

 forty square yards, or more. As the species had already been 

 extinct as a native plant in Huntingdonshire for nearly ten years, 

 I felt that in following Mr. H. C. Watson's advice of "helping" 

 a plant to live, I had done well ; and the plant being beyond all 

 danger of extinccion by any number of collectors, the time had 

 come when a notice of the introduction became necessary in this 

 Journal. 



On August 19th I was at the original locality in the parish of 

 Ramsey, and found no trace of any Potainoyetun whatever in the 

 little pit by the forty-foot drain, but some fifty yards away I saw a 

 new pit had been dug since my last visit in 1895. In this new pit 

 to my surprise I found some beautiful seedling forms of P. naUms, 

 with lanceolate, oval, and round floating leaves, sufficient to afford 

 examples of several named " varieties," but unfortunately all growing 

 on one rootstock in the instance in which the " varieties " were most 

 marked ! At one end of the pit a plant of nutans was growing 

 which looked older and more thoroughly established, and with much 

 the look oi fluitans about the mass of foliage. On closer inspection 

 I found several plants of Jluitans were really mixed up with the 

 nutans, and that native, unhelped specimens of Huntingdonshire 

 Jiuitans were still existing ! 



Now from whence did these plants come ? My former suggestion 

 {Joxirn. Hot. 1886, 307) that the species was brought down from 

 the upland waters of the county has received no support from an 

 examination of the only brook which runs into the forty-foot. 



• Jonrn. Bot. 1888, 277. 



2 A 2 



