Floristik, Geographie. Systematik etc. 59 



plentiful and formed small tussocks. Where Carex, Arundo Phrag- 

 mites and Pteris aquüina occurred growing together, much larger 

 tussocks were formed (height 1 2 metres, circumference 2 — 3 metres); 

 these tussocks in form suggested a tree-fern habit, the bases of 

 leaves of Pteris and Arundo persisting in a mass like a tree-fern 

 stump, the crown consisting of the mixed foliage. W. G. Smith. 



Weiss, F. E., A preliminary accoun t of the Submerged 

 Vegetation of Lake Windermere as affecting the fee- 

 ding ground of Fish. (Mem. Proc. Lit. and Phil. Soc. Man- 

 chester LIII. 11. 9 pp. fig. 1909.) 



A recent increase in Cladophora sp., Nitella opaca, Eiodea cana- 

 densis and other aquatic plants has resulted in interference with rod- 

 fishing. Descriptions are given of the form of Nitella met with. and of 

 Eiodea, including a historical summary ofits increase in Britain since 

 1836; the formation of winter-buds is illustrated. The increase of 

 these weeds began when net-fishing was restricted; the author points 

 out the Utility of nets in Clearing shallow parts from excessive plant- 

 growths, and recommends an increase of net-fishing in the Lake 

 as a means of preserving the feeding grounds of fish. 



W. G. Smith. 



Weiss, F. E., The Dispersal of the Seeds of the Gorse 

 and Broom by Ants. (New Phytol. VIII. 3. p. 81-89. 2 figs. 1909.) 



In continuation of previous observations (Bot. Cent. 108.' p. 172), 

 the author describes the distribution of plants of Ulex along a cart- 

 track across a Calluna heath, and of Ulex and Sarothamnus in a 

 wood with ant-heaps; in both instances the plants were traced from 

 colonies of older plants, and followed well-defined lines. Observations 

 made on the removal of seeds by ants showed interesting results; 

 5 seeds of Ulex placed on an ant-path were all removed in 10 mi- 

 nutes; in another instance when 9 seeds were laid down, 8 were 

 removed in 15 min.; and again 5 Ulex seeds in 10 min. On the other 

 hand 10 seeds of Arctium and Teucrium laid with Ulex seeds were 

 with one exception left untouched. 5 seeds of Sarothamnus were 

 removed in 18 minutes. The ants were observed to feed on the 

 caruncle of Ulex and Sarothamnus , although apparently they were 

 unable to perceive the presence of seeds by smell. The author 

 therefore proposes to include these two seeds amongst the myr- 

 mecochorus plants, and to attribute their dispersal amongst Calluna 

 and other plant associations to the agency of ants. W. G. Smith. 



Weiss, F. E. and H. Murray. On the occurrence and disper- 

 sal of some Alien Aquatic Plants in the Reddish Canal. 

 (Mem. Proc. Lit. and Phil. Soc. of Manchester LIII. 14. 8 pp. 1 fig. 

 1909.) 



The temperature of this canal is raised in places by the inflow 

 of heated water from cotton mills, and the authors have examined 

 the distribution of certain alien plants in relation to temperature of 

 the water. Vallisneria spiralis, originally planted, now grows in parts 

 with a temperature of over 70° F., Chara Braunii (Gmel.) has suc- 

 cessfully established itself, but Naias graminea var. Delilei (Magnus) 

 once abundant has now almost disappeared; both species are belie- 



