NOTES AND ABSTRACTS. 



149 



water. These seeds swell more in KOH than in NH.,OH, and more in either of 

 these than in Ca(OH).j or NaOH, in the order named. The kations Ca and Na 

 are apparently more active in bringing about a reduction in the water content 

 than either NH 4 or K. 



6. In equinormal solutions of acids and alkalies, it is found that these seeds 

 swell less and retain much less water in an acid medium than in an alkaline 

 solution. 



In similar experiments with seeds of Zea Mays, corroborative results were 

 obtained. 



In further experiments, cuttings of tomato plants were used. The chief 

 results obtained were : — 



1. During 15 days the cuttings absorb and transpire less water in an acid 

 solution than in distilled water. 



There is a great difference in the relationship between the quantity absorbed 

 and transpired and the concentration of the acid. A point is reached in the 

 solution of HC1 and H 2 S0 4 , beyond which a further increase or decrease in 

 concentration is followed by a diminished absorption or loss of water ; while in 

 solutions of HNO3 and CH a CO.OH (acetic acid) the absorption and tran- 

 spiration of water vary inversely as the concentration. 



2. At the concentrations employed, the absorption and transpiration of water 

 by tomato plants in alkaline solutions are less than in distilled water. The kations, 

 in their order of effectiveness, bringing about the least inhibition, are K, Na, Ca, 

 NH 4 . Beyond a certain optimal point a further increase or decrease in con- 

 centration leads to a diminished water relation. 



There is appended a short bibliography giving references to this subject. 



A. B. 



Acid Lands, Agricultural Utilization of, by means of Acid-tolerant Crops, The . 



By Frederick V. Colville {U.S.A. Dep. Agr., Bur. PI. Ind., Bull. Sept. 1913 .* 

 J 3 PP-)- — The author describes the use of certain acid-tolerant agricultural plants 

 where liming is an economic impossibility. — C. P. C. 



Acid Soils of Porto Rico, Studies on. By Oscar Loew (U.S.A. Exp. 

 Sin. Porto Rico, Bull. 12, Oct. 1913, pp. 23). — Some studies on the acid clays of 

 Porto Rico, showing the value of liming, the consequent increase of the azoto- 

 bacter, and the diminution of butyric ferments. — C. P. C, 



Aconitum rotundifolium (Bot. Mag. tab. 8575). — W. C. Asia. Nat. Ord. 

 Ranunculaceae, tribe Helleboreae. Herb, 6-16 inches high. Leaf-blades suborbi- 

 cular, much divided. Flowers in racemes. Sepals greenish- white, with violet 

 veins, and flushed with purple or violet. — G. H. 



Aesculus, New Species. By W. J. Bean (Kew Bull. No. 2, p. 50, 1914). — 

 A . chinensis (not A . turbinata, 'which has been grown under the name of A . chinen- 

 sis) introduced by Purdom in 1912, from North China, and A. Wilsonii, collected 

 by Wilson in West Hupeh, are described. The former appears to be quite hardy, 

 but there is still a little doubt about the latter. — F. J. C. 



Afforestation of Waste Lands, Average Returns from the. By 



P. Trentham Maw (Quart. Jour, of Forestry, vol. ix. No. 1, pp. 18-33 ; Jan: 

 191 5). — Many experts are fond of quoting examples of the returns obtained from 

 German forests, but evidence of this nature is apt to be most misleading. If 

 forests are properly stocked, and have approximately equal areas under crops 

 representing all ages from one year old up to maturity (when they are said to 

 be " normally stocked " ), they should, of course, yield a large average income 

 per acre, but the capital expended in obtaining that income is often enormous, 

 so much so that an income of £2. per acre may, in fact, prove to be a great loss 

 if the undertaking has been financed at 3 or 3^ per cent, interest. 



In conclusion, I desire to express the opinion that there are vast areas of 

 land below an altitude of 750 feet above sea-level which it would pay well to 

 afforest. Such land is now, much of it, let for farming purposes at rentals varying 

 from 5s. to 7s. per acre; whilst there are also huge tracts of equally good land 

 now lying waste, or subject to rights of common, the annual value of which is very 

 slight. Without doubt, upon economic grounds, much of this common land 

 should be afforested. There are, I know, difficulties in the way — commoners, 

 even if compensated, are loth to have their rights interfered with — and yet I 

 believe these difficulties are not insurmountable, if only they are approached in a 

 proper manner. — A. D. W. 



