FIELD CROPS. 629 



III an apitoiKlix, Miss .I«'iiii White jiivcs an acmnnt of (wiicrinicnts in wliicli 

 she found that hard si'inls whirli aiv iiK-a[»ablo of iuibil)inj;: water owe their 

 failure to tai<e uii water to tlie jiresence of a cuticular layer, and that when 

 this is removed or penetrated either by luechanical means or the action of 

 aeids, the seeds swell rapidly and, if tlu-ir vitality is sulHrient, ^'erniinate 

 quickly. 



It is claimed that Becquerel's conclusions that the impermeability of the 

 coats of macrobiotic seetls is a gradual result of their aging are incorrect. The 

 impermeability is due to the presence of a cuticle developed during ripening, 

 and its presence i>r absence determines whether a seed will or will not have 

 a long life in the soil, hut not whether it will have a long life when i)reserved 

 in dry air. Macrobiosis is the result of a biological adaptation of the i)roto- 

 plasni. in which an ininernieable cuti'-le i)lays a merely accessory or aiding part. 



Methods and causes of evolution, O. F. Cook (U. S. Dept. Agr., Bur. Plant 

 IihIus. Bill. l.iU, PI). 3-j). — A discussion is given of the methods and causes of 

 evolution, with special reference to the application of the ascertained facts to 

 breeding, acclimatization, etc. 



The present state of knowledge of heredity in Pisum, R. II. Lock (Ann. 

 Roil. Bot, (Uird. J'cradrniiitt, .) (I!K)S), \o. J. />p. US-Ill). — A summary is given 

 of the most imi)ortant facts so far recorded with regard to heredity iu Pisum, 

 and attention is called to some of the gaps which still remain in our knowledge 

 of the subject. 



The author states that the behavior of the color characters of the testa and 

 corolla has been worked out completely and described iu terms of Mendelian 

 segregation with the help of the idea of the masking of several characters when 

 certain other characters are absent. The principal gaps remaining in our 

 knowledge relate to the heredity of the purple pod and of the allelomorphs 

 concerned in determining the number and length of interuodes. 



FIELD CROPS. 



The revegetation of overgrazed range areas, A. W. Sampson and F. V. 

 CoviLLE iU. H. iJcpt. At/r., Forest ticrr. t'irc. 15S, pp. 21). — The work here re- 

 iMirted was conducted for the purpose of determining the relative inii)ortance 

 of the native grasses and forage i)lants on the Wallowa National Forest in 

 eastern C)reg(»n. and to ascertain the rapidity and extent to which the important 

 forest i)lants are regenerating niton overgrazed areas, what plants under the 

 jiresent grazing system are succeeding upon depleted range areas, and by what 

 system of grazing the foiiiier iiroduct iveness of the range may be rest<ired 

 through natural reseeding. 



Four zones of vegetation are recognizinl and described. Th(> lower, or yellow 

 I»ine zone, ranges in altitude from 3,0(»() to 4,.^»()0 ft. and its vegetation is made up 

 largely of bunch grass, those occurring in the greatest abinidaiice being blue 

 bunch grass {Fixtiicit arizonicit) , big bunch grass ( .Xtirnpiiroii xpU-atiuii). little 

 bhie grass { I'on xinulhcrtfii). and mountain .lune grass (Kulrria cristata). The 

 Itxlgepole pine zone occupies th<? altitudes ranging from 4,r>(M) to ('i.SOt) ft. The 

 most characteristic tret? of this region is the lodgepole pine. The open grass 

 land areas in the zone are comparativ«'ly small. While no particular grasses 

 are especially characteristic of this zone, smooth wild rye grass {Klinmis gJau- 

 vuH), sliort awned brome grass (Bromus marginutun), western neetlle grass ( t^tipa 

 (KTuli-nlaliM), and pine grass (Cnlaiiiaf/rostis .suksilorfii) are among the more 

 common sp«H'ies. The third, or whilebark pine zone, is from t».."i(M> to S.."»(K» ft. 

 above sea level and is nanie<l after its most typical tree. The most striking 

 features of this area are the great prei)ouderance of open grass lands and the 



