CANADIAN BIOLOGY 7 



SESSIONAL PAPER No. 38a 



ing various doubtful specimens obtained in the North sea and North Atlantic. The 

 smallest specimens, wormlike in form, range from ^ inch to | inch in length, and when 

 pigment appears, it forms four indefinite rows of black spots along the body, on each 

 side, and extends over the median unpaired fins. The flattened form is gradually 

 assumed, and when the length of 1 inch in reached, coloured cross bands, seven in 

 number, appear on the two large median fin-expansions. Dr. Schmidt, the Danish 

 biologist, obtained specimens of the last-named size in 60 fathoms in the month of 

 May. The fish at 34 mm. (1;\ inch) though still more flattened, continue to swim on- 

 edge, and on the right side the dark colour is more pronounced. A mottled arrange- 

 ment of colour is soon assumed, and this is a feature which is characteristic of the 

 halibut during post-larval life. At the length of 5 inches the full-grown features are 

 assumed, and specimens of that size were obtained by Professor Verrill in the straits 

 of Canso, and Scottish specimens, 12 inches in length, are recorded by Professor 

 Mcintosh on the east coast of Scotland ; and halibut rather smaller (10 inches long) 

 are common in shallow waters around Iceland. Dr. Wemyss Pulton is of the opinion 

 that small halibut move into deep water in the late sunlmer, and in October he 

 obtained Scottish specimens, 17^ to 30 inches long, at a depth of 65 fathoms. 



The less common species of halibut (Hippoglossus liippoglossoides, Walb.) is dis- 

 tinguished in its youngest stages by lack of colour, and when J inch long is still very 

 sparingly spotted, in contrast to the familiar species H. hippo glossus. 



III. — BRITISH COLUMBIA KELP BEDS (PROF. A. T. CAMEROn). 



The third report on " The Kelp Beds of British Columbia," by Professor Cameron, 

 Winnipeg, presents an account of an important research, treating specially of the two 

 most valuable species, the bull-kelp and the sea-ivy, or long bladder kelp. These two 

 species of Laminaria are commercially valuable as they yield more potash than Puci 

 and other rock- weeds, and can be more easily harvested. The former, the bull-kelp, 

 occurs all round the British Columbia coast, but the latter, the sea-ivy or flag-weed, 

 is absent in regions where the water is of diminished salinity. Both require a rocky 

 shore for firm attachment, and a tidal flow, three to five knots per hour, a salinity not 

 less than two-thirds ocean salinity (mean density, 1-019), and a suitable temperature. 



The bull-kelp grows in spring, but decays rapidly after July, the crop being 

 thickest from July to October. The beds are visible, however, all the year, as new 

 plants attain some size before the old plants die. They spread asexually by spores. 

 Possibly in late July, harvesting of the beds should commence, after the spores have 

 been discharged. 



The sea-ivy has a life longer than a year, and spores are produced on fronds 

 towards the base or root, and the species can thus be more readily harvested than the 

 bull-kelp. 



Dr. Cameron estimates the extent of available Pacific beds, and indicates their 

 location on a map specially prepared by him. He describes as " thick beds " those on 

 which there is at least one plant- to a square yard ; though there may be three, four, 

 or more. The portions commercially available in each plant range from 5 to 8 pounds 

 to 24 pounds, the average being about 12 pounds per plant, and one mile of coast line 

 should yield 245 tons, or a total British Columbia harvest annually of considerably 

 more than 400,000 tons of kelp. Some areas are more productive than others. On 

 Queen Charlotte islands, each plant would yield 15 to 20 pounds of raw material. The 

 amount of water in the tissues of kelp is, of course, large, namely, 92 per cent, in the 

 fronds, with 8 per cent dry matter ; the stock, 874 ; and 123 dry matter ; root or hold- 

 fast, 87i and 12* dry matter. The air-bladder contains 94 per cent of water and only 

 6 per cent dry matter. Assuming that the potassium chloride is 30 per cent and valued 

 at $50 per ton, and the iodine -12 per cent and valued at $38.75, the total value per 

 annum would, for the former, be $11,750,000, and for the latter $3,680,000, or a total 



