AQUATIC FORMS AND SPECIES OF THE BRITISH FLORA Ig 
among higher vegetation in wet or damp places, but in 
Barlockhart Loch, Wigtownshire, Mr. West gathered a 
“floating form having stems 30 to 50 inches long, with 
leaves only $ inch in diameter and very thin.” 
5. Aptum tnundatum, H. G. Reichb.—This species varies 
considerably as to depth of submerged forms. I have seen 
it in water 2 feet deep. Mr. West records it “in water from 
3 feet to 6 feet deep, reaching the surface from even the 
greatest depth.” In Engler’s “Bot. Jahrbiichern,”1 Dr. 
Glick throws these various semiaquatics into groups under 
three series (p. 140)— 
1. Die submerse form, 
2. Die Schwimmblattfiora, 
3. Die Uferflora, 
placing this species with “ Szawm latifolium, Ginanthe fistulosa, 
. fluttans, Littorella lacustris, etc.” 
Mr. West (2) remarks: “In some places, where the water 
has retreated, the seedlings grow so thick as to cover the 
mud with a sward, but their further development in an aerial 
environment is restrained.” 
6. Ceratophyllum demersum, L.—Not from any submerged 
point, but as a remarkable instance of distribution, I mention 
this. In the whole of the Loch Ness area, the island of 
Lismore, and Nairn ; then in Kirkcudbright, Wigtown, Fife, 
and Kinross (140 lochs), only once did Mr. West collect this 
species. In Otterston Loch (Fife) “it grows in such extra- 
ordinary abundance that in many places a boat can only be 
rowed through it with difficulty.” This I have experienced 
in Norfolk, where in Blackfleet Broad it was impossible to 
force the boat through it; it there grew intermingled with 
Chara polyacantha in thick masses. 
7. Juncus suptnus, Moench.—In this we have another 
species that passes from a strictly terrestrial form through 
many phases to an extreme one in var. fluztans. I have 
not been able to absolutely trace the submerged form to a 
terrestrial form, and cultivation is required here, which is 
just what Dr. Gliick is doing at Heidelberg. We seem to 
possess— 
1. The type as var. xodosus, Lange. 
1 “ Uber die Lebensweise der Uferflora,” 1909, pp. 104-119. 
