42 
good enough to examine all my British Potamogetons, and 
he also was doubtful as to the proper nomenclature of the 
Derwent water specimens of 1870, thinking that it might be 
P. Zizii , although showing an approach to P. decipiens in 
the structure of its leaves. 
The uncertainty about this plant, therefore, led me to 
make a careful search for fruiting specimens in Derwent- 
water, during a visit in September last. The station in 
which the plant was the most abundant in 1882, is in the 
easternmost of two small bays which lie to the east of the 
outflow of the lake. The plant grows with Scirpus lacustris, 
L., in about four to six feet of water, and there are several 
colonies of it. Out of some hundreds of plants examined 
in situ there were but two flowering specimens, one of 
which is now exhibited to the members, and the other was 
sent to Mr. Arthur Bennett, who pronounced it to be 
P. Zizii. 
Later on, on the 22nd September, 1882, I found the same 
plant growing in the greatest profusion at the northern end 
of Coniston Lake, and flowering abundantly, nearly all the 
plants being in flower or fruit. I had no means of ascertain- 
ing the depth of the water, but in many places it would not 
be less than eight or ten feet ; the longest specimen actually 
gathered was six feet long. I also saw the same species 
growing in Windermere, on the western side, near the new 
Ferry Hotel, but I could not collect it as I was on the steam 
ferry at the time. 
According to the notes of Mr. Andrew Brotherston in the 
Reports of the ‘Botanical Exchange Club’ for 1879, and of 
the ‘Botanical Record Club’ for 1878, the plants from 
Cauldshiels Loch grew in water less than one foot deep in 
1878, and two feet deep in 1879 ; Mr. Brotherston’s speci- 
mens of each of these two years’ growths, now exhibited for 
comparison, show considerable difference in habit; the 1878 
plants possess short internodes, and subsessile leaves which 
