FIELD CROPS. 739 



tion was found to corrospoiul to a concoutration of tho pigmpiit equaling that 

 found in younp leaves of shade-loving and old leaves of sliade-shunning species. 

 .Vduli leaves of tolerant species apsiniilate less energetically than adult leaves 

 of those species which are intolerant of shade. 



From a biological standiioint, the concentration of chloroi)hyll in the chloro- 

 plasts may he considered as a means for adapting plants to the different de- 

 grees of illumination found in their habitats. Tolerant species, by increasing 

 the concentration of their pigment, are able to withstand a relatively feeble 

 illumination, and a brightly lighted situation is injurious to intolerant si)ecies 

 in so far as they are unable to vary the concentration of color in the chloro- 

 plasts. The intolerant species have a less concentrated chlorophyll in the 

 natural state than the tolerant ones. 



Does the chemical substance called chlorophyll exist? M. Tsvett ( R<r. 

 (J^n. Bot., 20 (IDOS), \o. 236, pp. 328-331).— The author presents arguments to 

 show that what has been heretofore called chlorophyll is not a simple chemical 

 substance, but is a mixture of 2 coloring materials, to which the names chloro- 

 phyllin a and chlorophyllin /3 are given. The fii'St gives a blue color in a solu- 

 tion of ether and generally is 4 or 5 times as abundant as the second, which 

 gives a green color when extracted with ether. 



The influence of nutrition, water, and illumination on the development 

 p.nd organization of higher plants, Runger (Natunr. Wchnsichr., 23 (l'.>OS\, 

 .\(t. .}.J. pji. (n3-iisi!). — A summary and critical review Is given of some of the 

 more recent litcriiture relating to the intiuence of nutrition, water, and light 

 on plants. 



FIELD CROPS. 



Variety selection, seed culture, and plant breeding in Wiirttemberg'. 

 < '. l-'RrwiRTii {Sorfin, Sadlfniclillxni iiml I'/lniKciiziiclitinifi in Wiirrtfcmlxrij. 

 I'liriiinf/rn, tUOl. pp. 'i3). — This jiublication in discussing varieties, selection, 

 and dissemination touches u|>on tlic earliest work of this kind, the variety tests 

 made before and after the establishment of the plant-breeding station, the 

 distrilmtion of the varieties in tho country, and the varieties connnonly grown. 

 The history of se(>d production is reviewed, the promotion and direction of seed 

 culture jit the iilant-bre<>diug station is described, and notes on the different 

 establishments making a specialty of seed and i)otato culture are given. 



I'nder plant breeding the author discusses the development of breeding in 

 Wiirttemberg aiirl other i>arts of (Jermany. and enumerates the farms which 

 began jdant breeding by themselves, as well as tho.se which cooperated with 

 the plant-breeding station. The methods of carrying on this work at the station 

 are also outlined. 



Report of the government agrostologist and botanist, .7. IiURTT-I>AVY. 

 I. H. r. Evans, and II. (J. Mi'Nuy ( Tniiisraul ftrpf. Aj/r. Ann. lipt. 1907. pp. 

 132-1 'iH, hl-'i-ni). — This report contains brief reviews of the different lines of 

 work carried on during the y«':ir. Notes are given on veld or range improve- 

 ment, tlie culture of a long list of miscelljineons crops, the prevalence of noxious 

 w«hh!s and i>oisonous plants, jilant diseases and insect enemies, and the intro- 

 duction of wH'ds and plants. In cultural tests with corn yields ranging from 

 l,li(Ki to 4,(MMt lbs. |H*r ac-re an- reported. 



Dry fanning in Wyoming, V. T. Cookk (Tran.><- Missouri Hrii Farm. ('fnu/. 

 Itiil. I. pp. 13, pi. /).— A bulletin published by the State Dry Farming t'om- 

 niissi«)n and containing brief directions for farming dry lands in Wyoming. 



Rules for the uniform seeding of grains for comparative botanical investi- 

 gations il'iiiiliii liiimu I'rihl. Hot., I {I'JOS), \t,. 1-2. pp. .S6'-^'.'/ ).— Uules are 

 TTISIV- 00 1 



