l!^-0] AGRICULTURAL BOTANY. 521 



iinalysrs of ."SS s;iiiii)lcs (if fertilizers and fertilizer materials r(»IIe<t('<l in New 

 York during; IMli). 



Fertilizers: Xotes on sprins; fertilizer inspection ( \'a. Drpt. .\(jr. and 

 Inunif/r. Jiiil. J52 (1920), pp. 18-27). — Analyses of 02 .samples of fertilizers and 

 fertilizer materials offered for sale in Virginia during the spring of 1920, and 

 wliich were either hadly or slightly deficient in one or more plant-food con- 

 stituents, are reported, together with a list of some 270 brands which were 

 found to meet the guaranty in all respects. 



Analyses of four samples of burnt lime, three samples of unburuL lime, and 

 one saniple of lime and iiotasli are also reported. 



AGRICULTURAL BOTANY. 



The causes and course of organic evolution: A study in bioenergics, .T. M. 



.M.vcFARLANE (Xi'iv Yovk: The Macmillan Co., 1D18, pp. 875, pis. 5, flys. 25). — 

 The author snythesizes herein the results of study carried on during a long 

 period in many fields, together embracing the whole range of biotic activity. 

 He emphasizes the facts and bearings of evolution in its different forms 

 throughout the course of plant and animal life. Energy, continuity, and evolu- 

 tion together form the keynote of this volume. A long list of related literature 

 is given. 



Visibility of Mendelian splitting in pollen of CEnothera hybrids, O. Ri-.x- 

 KER {Her. Dent. Hot. Gesell., 37 (1919), No. 2, pp. 129-135, fi(is. 2).— Pollen 

 grains of the hybrid Oenothera (lamarckianaXmvricata) gracilis show even 

 imder low magnification a clear differentiation as regards size of the pollen 

 grains and form of granulations therein. 



(Knothera laniarckiana mutant simplex, H. de Vries (Ber. Deut. Jiof. 

 Gesell., 37 (1919), No. 1, pp. 65-73). — A mutation appearing in 1906 and named 

 (K. Unnnrehiana •simplex is here discussed in its i-elations with other forms. 



Further experimental studies on self-incompatibility in hermaphrodite 

 plants, A. B. Stout (Jour. Genetics, 9 (1920), No. 2, pp. 85-129, pis. 2).—Thifi 

 lejMirt represents an extension of experimental studies previou.sly noted (E. 

 S. K.. 40, p. 427), continuing to yield evidence that compatible and incom- 

 patible relations of the sex organs (including germ cells) in the fertilization of 

 hermaphrodites are highly fluctuating in the progeny of single cross- or self- 

 fertilized descent. There are all grades in the degree to which both self- 

 compatibility and cros.s-conipatibiiily may appear, and even the reciprocal 

 niatings of two hermaphrodites may give opposite results. 



It is assumed that within the species both self- and cross-compatibility con- 

 stitute the rule, reiu-esenting the primitive condition. Incompatibilities are 

 special ca.ses. Cross-sterility within a species is a relatively rare phenomenon, 

 often accomplished by such morphological modifications in the sex organs as 

 dimorphism. Self-incompatibility is more common and appears to have a 

 value in connection with natural selection. It appears from its wide distri- 

 bution to have ari.sen often indeiiendently, and it is argued that it may be of 

 fundamental significance. 



The evidence is considered to favor the view that self-compatibility is a 

 progre.ssive character. Intensive study of fertility of feebly self-compatible 

 individuals yields positive evidence as to how .self-sterility has arisen in species 

 originally self-fertile. The marked fluctuation of the character In practically 

 all self-sterile species is regarded as specially significant. More recent studies 

 than those above noted are said tp have yielded additional support to the 

 general co^ejivsiojjs that follow. 



