NOTES AND ABSTRACTS. 



131 



the vine and fruit of single-stem tomato plants can take up the follow- 

 ing ingredients from each 100 square feet of trench : nitrogen, 168 

 grams, equal to nitrate of soda 2 lb. 5 oz. ; phosphoric acid, 65 grams, 

 equal to boneblack 13 oz. ; and potash, 362 grams, equal to muriate of 

 potash 1 lb. 9 oz. Of this amount nearly four-fifths went into the 

 fruit (p. 567). The mere fact, however, that a plant will take up a 

 certain amount of fertilizer is not in itself sufficient evidence that 

 that amount of fertilizer is required (p. 568). Too much lime is said 

 to produce excessive stem and leaf development and a diminished yield 

 of fruit, while watery fruits are said to be richer in ash content 

 than the more fleshy ones (p. 569). Soil sterilization is recommended 

 for greenhouse work, and four methods of doing it on a commercial 

 scale are described (pp. 555 and 573). — A. P. . 



Filmy Ferns in Jamaica. By F. Shreve (Bot. Gaz. March 

 1911; with 8 figs.). — The author first gives an interesting account of 

 the distribution of the filmy ferns in Jamaica. They are most abun- 

 dant at 1525 metres altitude. Some are confined to very moist con- 

 ditions, whilst a few, mostly epiphytes, are able to endure almost as 

 great a loss of water as mosses and ferns. The local distribution in 

 the rain forests is determined by the differences in climate from the 

 floor to the canopy. The author describes many experiments which 

 show that almost all can meet loss of water from surface-dry leaves 

 in a very moist atmosphere by root absorption. The transpiration 

 current moves even when the leaves are wholly or partly surface-dry, 

 but stops when the leaves are thoroughly wet. All, except the most 

 drought-resisting forms, can exist as submerged aquatics. These 

 xerophytic epiphytes can absorb atmospheric moisture in very moist 

 air. The latter species have an intracellular or functional xerophily; 

 the protoplasmic lining of the cells survives the replacing of the sap 

 cavity by air, and even a considerable loss of water. — G. F. S. E. 



Floats. By E. W. Gaither [U.S.A. Exp. Sin., Ohio, Circ. 105, 

 Sept. 1910). — This is the commercial name for finely ground phosphate 

 rock, a natural formation of tricalcium phosphate. It is usually of 

 too low a grade to be used in the manufacture of acid phosphate, but 

 it has been found that on clay and silt loam soils decaying organic 

 matter and bacterial action render it sufficiently available to plants 

 to make its use in connexion with farm and green manures both 

 profitable and desirable. The material should contain not less than 

 26 per cent, phosphoric acid, and not more than 8 per cent, of oxides 

 of iron and aluminium combined ; while it should be sufficiently finely 

 ground to enable not less than 93 per cent, of it to pass through an 

 eighty-mesh sieve. The question of the relative availability of kiln- 

 dried and sun-dried floats is still being investigated. — A. P. 



Florida, Report on a Visit to. By H. A. Ballon, M.Sc (West 

 Indian Bull, vol, xi, No, 3, 1911).— This visit was made for the 



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