NOTES AND ABSTRACTS. 



835 



supplies suffice to produce maximum crops throughout rotation. For this 

 reason it is found to be profitable to purchase artificials, which, however, 

 should be regarded as a supplement, not as a substitute, for the natural 

 fertiliser. Formulae are given for cereals and roots, and also for Cabbages, 

 Carrots, Parsnips, Beans, and Peas. — B. N. 



Manurial Treatment of Poor Pastures: Soil Analysis as a 

 Guide to. By T. B. Wood and R. A. Berry (Jour. Agr. Sc. vol. i. 

 part i., pp. 114-121, Jan. 1905). — A record of some experimental work 

 which shows the superiority of the citric-acid method of determining what 

 manures are likely to give successful results, as compared with the determi- 

 nation of the percentages of "total" nitrogen, phosphoric acid, &c. If 

 the citric acid test shows the "available" phosphoric acid to be below 

 002 per cent, on pastures, there is a probability of successful phosphoric 

 manuring. Similarly, if there is less than 0*01 per cent, of " available " 

 potash, there are likely to be distinct results from potash manuring. 

 " Liming is not indicated as likely to be profitable unless the soil contains 

 certainly less than 0*5 per cent, of chalk." 



" That basic slag is nearly always a better source of phosphoric acid 

 for pastures than superphosphate, unless, perhaps, when the soil contains 

 an exceptionally high percentage of chalk." 



" Determinations of citric acid, soluble phosphoric acid and potash, 

 and of calcium carbonate, and mechanical analysis of the soil, together 

 with careful observations of the herbage which the land in its unmanured 

 condition is producing, may be expscted to indicate clearly those soils 

 which are likely to be improved for pasturage by manuring with phos- 

 phates and potash." — F. J. B. 



Maple Leaves, Anatomy of. By Georg Warsow (Beih. Bot. Gent. 

 xv. pp. 493-601 ; with four text figures). — Gives a thorough description of 

 anatomical details in the leaves of 110 species of Acer. The character of 

 the epidermis cells with presence or absence of papilhe and a wax layer, 

 character of mesophyli, trichomes, crystals, laticiferous elements, &c. are 

 fully detailed for each of those species, and a table of the distribution of 

 the species and the more important results is appended. In twelve species 

 the so-called "laticiferous " secretion has been found. — G. F. S.-E. 



Maple Sap Flow {U.S.A. Agr. Exp. Stn. Vermont, Bulls. 103 and 

 105, December 1903, February 1904). — Two excellent reports on the 

 practical and theoretical problems suggested by the Maple Sap Flow. 

 The authors frankly state that " their observations on the Sugar Maple 

 have raised more questions in their minds than they have answered " ; 

 but the bulletins are a model of clear and concise statement of facts 

 determined, as well as of theories discussed. Commendable, too, is the 

 plan of issuing the full reports in No. 103, and a condensed popular 

 edition in No. 105 (containing summary, introduction, general structure 

 and physiology, sap pressure and flow, sugar orchard problems) ; but 

 those interested in the general physiological bearing of the subject should 

 not neglect the fuller exposition. 



1. Whence comes the S2tgar ?■ And what relation has the structure of 

 the tree and its life functions to sugar formation ? — Maple sugar is 



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