AGRICULTURAL BOTANY. 433 



Analyses and valuations of commercial fertilizers, J. 1'. SruKirr, W. P. 

 Allkn. and V. J. Cakueuuy {\<ir .Inscii Stux. Bill. V.Ml, pp.,.i.7 ).— This bullotin 

 reports analyses of 205 brands of complete fertilizers, 102 samples of unmixed 

 Ccrtiliziiig materials. 5 home mixlures, and 20 special fertilizers examined dur- 

 ing; the s])rinjj: of 1900. 



Fertilizers and feeding stuffs act, 1906 {Mark Lane Exprcsa, 95 {1906). 

 \o. 3911, pp. 27.'/. ,?7.7). — The text of the revised British act is fiiven and the 

 principal points on which it differs from the old are briefly summarized. 



AGRICULTURAL BOTANY. 



Flora of Colorado, 1'. A. Kydiskuu {VohiraiJo Hia. liiil. UK), p/i. XXJI + //-'/.S).— 

 This catalogue of species is based mainly upon the collections of the agricul- 

 tm-al college at Fort Collins and the herbaria at the New York Botanic Gar- 

 den, with additional records secured from other sources. The author has pre- 

 sented keys to the gimera and species and under the siiecific name gives briefly 

 (he habitat and distribution of the plant. 



'i'he publication as presented stands as a brief index of the present knowledge 

 of the flora of the State, and it Is believed that it will be of use to all systematic 

 botanists, to the schools of the State, and to all interested in the economic study 

 of Colorado plants or in the flora of the plains and mountains of Colorado. 



Role of seed coats in delayed germination, W. Crocker {Bot. Gaz., 42 

 (10(11)). \(i. '/. />/*. 2i).j-.>91, fi(/s. -J). — A study has been made of some of the 

 causes of delayed geruunation which is reported in seed of many plants, and 

 contrary to the common view that the cause is generally to be found in the 

 em])ryo the author finds that the structure of the seed coats is the determining 

 factor. 



Specific instances are given of delayed germination due to various peculiari- 

 ties of seed coats. The author finds that seed coats which exclude water are 

 much more liable to delays in germination than are seed coats which exclude 

 oxygen. In nature, growth of delayed seeds comes about by the disintegration 

 of the seed coat structures by longer or shorter exposure to germinative con- 

 ditions. 



In the case of seeds of the hawthorn there were found to be characters in 

 the eml)ryo which delayed germination, and in these instances the germina- 

 tion finally comes about through long exposure to germinative conditions but 

 not in di*y storage. The phenomena in delayed germination in the case of the 

 cocklebur, various species of IMantago. and other i)lants are described. 



The influence of sunlight and diffused light on the development of sugar 

 beets, S. Strakoscii {Hcparalc from (jstcrr. I'liijar. Ztschr. Ziickcriiidiis. ii. 

 Laiulv:, 19(l(), A'o. 1, pp. 11, fii/x. 2). — The sugar beet, it is claimed, can form all 

 the starch necessary to its growth in very diffused light. Nevertheless direct 

 sunlight stiuuilates the formation of sulistances in the plant such as starch. A 

 lack of direct sunlight increases the nonsugars in the beet juice as well as re- 

 duces the total sugar content. The latter, however, is not influenced in the 

 same proportion as is the total size of the beet root. 



Under similar conditions there is a greater amount of intracellular respira- 

 tion in normal leaves than in those grown in greatly diffused light, although 

 the latter show a stronger ei)idermal transpiration. In conipariiig sun and 

 shade produced leaves the stomatn of those grown in lull light were found to 

 be larger, and relatively more slom.-ita were found on the ui)per and fewer on 

 the lower sides of the leaves. 



Translocation of the results of assimilation was continued longer in the case 

 of shade-produced leaves. \Yith an increase in light intensity tlici-e was ft)und a 



