in Extra-Tropical Countries. 295 



For this purpose branches of Quercus serrata are placed in shallow 

 bays, where Porphyra occurs, during spring, and the crop is obtained 

 from October to March, the seaweed being consumed in its young 

 state. It grows best, where fresh water enters the sea. Porphyra 

 contains about 26 per cent, of nitrogenous substances (with more than 

 4 per cent, of nitrogen) and about 5 per cent, of phosphate of potash. 

 In Japan, according to the catalogue of the International Exhibitions 

 of Sydney and Melbourne, the following Algae are also consumed for 

 food; Gloiopeltis intricata, G. capillaris, Laminaria saccharifera, two 

 species of Phylloderma, Phyllitis debilis, Kallhymenia dentata, Capea 

 elongata, Alaria pinnatifolia, G-racilaria lichenoides, G-. confervoides, 

 Enteromorpha compressa, species of Cystoseira and Halochloa, Codium 

 tomentosum, Mesogloia decipiens and Gelidium corneum. 



Populus alba, Dodoens. 



The Abele or White Poplar, indigenous to South-Eastern Europe, 

 North- Africa and Northern and Middle Asia, extending to North- 

 China, growing on the Himalayas up to 10,000 feet, ceasing at 4,000 

 feet. In Norway it is hardy to lat. 67 56' (Prof. Schuebeler). 

 Height reaching 90 feet. Emits suckers. It has proved an excellent 

 avenue-tree, even in comparatively waterless situations, and the partial 

 whiteness of its foliage gives a pleasing effect in any plantation. A 

 Silver-Poplar at Slowitz attained a basal stem-diameter of 20 feet, in- 

 dicating according to Pannewitz an age of probably 400 years. The 

 wood is pale, with a reddish tinge, brown near the centre, soft and 

 light. It can be used for flooring; it is particularly sought for trays, 

 bowls, bellows and shoe-soles; also, according to Porcher, for wooden 

 structures under wa.ter. " Sparterie" for plaiting is obtained from the 

 wood-shavings. The wood of this and some other poplars is easily 

 converted into paper-pulp, which is cheaply bleached. Lines of pop- 

 lars along forest-streams prevent or impede the progress of wood-con- 

 flagrations. The roots of poplars spread widely. P. cauescens (Smith), 

 the Grey Poplar, is either a variety of the Abele or its hybrid with 

 the Aspen, and yields a better timber for carpenters and millwrights. 



Populus angulata, Alton. 



Eastern North-America. The " Water-Poplar " or Carolina-Pop- 

 lar. Acquires a height of about 70 feet; branches very spreading; 

 hence this species well adapted as a promenade-tree. 



Populus balsamifera, Linn. 



The Tacamahac or Balsam-Poplar of the colder, but not the coldest 

 parts of North- America; also in Siberia and on the Himalayan Moun- 

 tains, where it ranges from 8,000 to 14,000 feet. "The balmiest of all 

 trees" called by Dr. Kellogg. It will endure the winters of Norway 

 to lat. 69 40' (Schuebeler). It attains a height of 80 feet. The tree 

 may be lopped for cattle-fodder (Stewart and Brandis) . Professor Mee- 

 han says that it will grow near the ocean's brink. Its variety is P. 

 candicans (Aiton). Acknowledged as a distinct species by Wesmael. 



u 



