1917] AGRIOULTUEAL BOTANY. 729 



inspection in Maine during 1916. It was found that on tlie whole the" fertilizers 

 analyzed were well up to the guaranty. 



Analysis of fertilizers for 1916, B. E. Cueey and T. O. Smith (New Hamp- 

 shire Sta. Bui. 179 {1916), pp. 10). — This bulletin contains the results of actual 

 and guarantied analyses of 140 samples of fertilizers and fertilizing materials 

 collected for inspection in New Hampshire during 1916. It is stated that a 

 little less than half the brands inspected carried 1 per cent of potash. 



AGRICULTURAL BOTANY. 



Experimental studies in the physiology of heredity, F. F. Blackman et al. 

 (Abs. in Rpt. Brit. Assoc. Adv. Sci., 85 {1915), pp. 233, 23//).— This is the re- 

 port of a committee of the association, giving a summary of the work being 

 carried on by R. P. Gregory and H. B. Killby, by the latter alone, by Miss 

 Gairdner, and by Edith R. Saunders (E. S. R., 34, p. 822). 



The studies on the genetics and cytology of the tetraploid races of Primula 

 sinensis have been continued, and progress has been made in the recognition and 

 testing of the heterozygous types AAAa, AAaa, and Aaaa. The phenomena of 

 coupling and repulsion have been further studied in both the diploid and tetra- 

 ploid races. 



The work has been continued on beans and vegetable marrows, on wall 

 flowers and Tropseolum, and on foxgloves and stocks. In case of the last named, 

 it appears possible to show how an ever-sporting type may be synthesized from 

 a true breeding individual. Further progress has been made in the study of 

 the inheritance of the half-hoary character and in the identification of theo- 

 retical types not found in commercial material. Evidences indicate that exces- 

 sive percentages of doubles quoted by growers are due to unconscious selection 

 and that the actual output of doubles is not in excess of that required by theoi-y. 



The calculation of linkage intensities, R. A. Emerson {Amer. Nat., 50 

 {1916), No. 595, pp. 411-4^0, fig. 1). — Discussing the methods in use for esti- 

 mating the intensity of linkage, the author presents formulas for use in the 

 approximation of gametic ratios directly from the Fj data, without the use of 

 coefficients of association and without respect to whether coupling or repulsion 

 is involved. A single formula leading to accurate results in either case is given, 

 together with others developed from this fundamental formula. 



Morphology and evolution of leaves, O. F. Cook {Jour. Wash. Acad. Sci., 

 6 {1916), No. 15, pp. 537-547) .—The author, discussing the primitive function 

 of leaves and the course and results of specialization in the variously related 

 structures, states that leaves of angiosperms show a primary division into a 

 basal sheath and an expanded blade supported thereby, as represented in leaves 

 of palms, grasses, and other plants. The organs usually described as petioles 

 appear to have arisen through the narrowing of the base of the blade or the 

 primitive sheath. The name foot is suggested as appropriate for the specialized 

 portion of the leaf sheath that serves as a petiole, both petiole and foot being 

 represented in several families named. The author considers also as speciali- 

 zations of the primitive sheath element such structures as stipules, bud scales, 

 bracts, ligules, pulvini, and probably even the blade itself. 



Preliminary observations on the nature and distribution of the statolith 

 apparatus in plants, Miss T. L. Pbankard {Abs. in Rpt. Brit. Assoc. Adv. Sci., 

 85 {1915), p. 722). — Statoliths, or bodies free to fall within the cell (statocyte) 

 which contains them, are found in various forms in different parts of plants 

 throughout a wide range of classification. These bodies are not universally 

 connected with the presence of starch. Statoliths are often chloroplasts and 



