822 EXPERIMENT STATION EECORD. (Vol.36 



Cost of ground limestone, C. W. Montgomery (Ohio Sta. Bui. SOS (1916), pp. 

 152. 15S. fiq. 1). — At the Hamilton County experiment farm tlie total coat of 

 crushing limestone was found to be $1.90 per ton as against a purchase price 

 for ground limestone of $3.24. including freight and hauling. 



Special fertilizer analyses, 1916, R. E. Rose and F. T. Wixson (Fla. Quart. 

 Bui. Dept. Agr., 27 (1911), No. 1, pp. 63-8/).— Analyses of 224 special samples 

 of fertilizers and fertilizing materials offered for sale in Florida during 1916 

 are reported. 



Official fertilizer analyses, 1916, R. E. Rose and F. T. Wilson (Fla. Quart. 

 Bui. Dept. Agr.. 21 (1911), No. 1. pp. 82-108). — Actual and guarantied analyses 

 of 180 official samples of fertilizers and fertilizing materials collected for in- 

 spection in Florida during 1916 are reported. 



Inspection of commercial fertilizers, 1916, H. D. Haskins, L. S. Walker, 

 C. P. Jones, and W. A. Allen (Massachusetts Sta. Control Ser. Bui. 6 (1916), 

 pp. 9S). — This bulletin gives a list of fertilizer brands registered in Massachu- 

 setts in 1916, and reports the i-esults of actunl and guarantied analyses of 800 

 samples of fertilizers and fertilizing materials collected for inspection in the 

 State during 1916. A summary is given showing average composition, cash 

 price, and cost per pound, of each element of plant food, and special attention 

 is called to commercial shortages and to the general character of the plant food 

 contained in brands of mixed complete fertilizers and ammoniated superphos- 

 phates. Twenty-five per cent of the mixed complete fertilizers analyzed fell 

 below the guaranty, over half of these being deficient in potash. On the average 

 51.7 per cent of the total nitrogen in the complete fertilizers was present as 

 nitrates and ammoniates, while 48.3 per cent was present as organic nitrogen. 

 Tests by means of the alkaline permanganate method gave additional proof of 

 the low availability of some of the organic nitrogen. 



A summary is also given of several hundred tests of the lime requirements 

 of Massachusetts soils. 



AGRICULTURAL BOTANY. 



The physiology of cell division, G. Habeblandt (Sitzber. K. Preiiss. Akad. 

 Wiss., 1913, XVI, pp. 318-345, figs. 1; 1916, XLVI, pp. 1096-1111, figs S).— The 

 work reported in these two articles was carried out first with sections from 

 potato tubers, then with material from stems of other plants, and finally with 

 leaf sections. It is said to have given increasing evidence that a stimulating 

 substance is separated from the phloem bundles, which, in connection with 

 wound stimulus, causes or promotes cell division and growth in the tissues in 

 the immediate neighborhood of the vascular bundles. 



On the liquid pressure theory of the circulation of sap in plants, Sarah 

 M. Baker (Abs. i» Rpt. Brit. A.ssoc. Adv. Set., 85 (1915), pp. 122, 123).— The 

 author, discussing two main current theories regarding the ascent of sap, 

 proposes one based primarily upon the ecological evidence that high trees grow 

 only where water vapor can have access to their roots. 



It is stated that when either droxight. low temperature, or an excess of liquid 

 water decreases the vapor supply beyond a certain limit, trees disappear and 

 the new plants which appear show marked xeromorphy. Experimental evidence 

 is said to support the theory which assumes that the root hair zone is special- 

 ized for salt absorption and permeable to liquid water, likewise that the grow- 

 ing region of the root tip Is impermeable to liquids but permeable to water 

 vapor (hence called aeropermeable), this region also being concerned in the 

 pumping efliciency of the root tip. Such an aeropermeable membrane, per- 

 mitting liquids to pa.ss in one direction but not in another, would render avail- 



