226 EXPERIMENT STATION RECORD. [Vol. 38 



cessful in develoiiiug these organs. TLis fungus, however, consistently pro- 

 duces, under widely varying conditions, resistant spores of nonsexual origin 

 and distinct morphological characters, differing from the gemma? des(;ribed for 

 other species in llieir regular occurrence and clearly defined structure. It is 

 legarded as an Achlya that has lost its power of sexual reproduction, the re- 

 sistant character usually assumed by the reproductive bodies of sexual origin 

 having in this case been taken over by the nonsexual resistant spores. 



Fertility in Cichorium intybus: The sporadic occurrence of self-fertile 

 plants among the progeny of self-sterile plants, A. B. Stout (Amcr. Jovr. 

 Hot., k {J917), No. 7, pp. StS-SUS, Jigs. 2).— The author, reporting with discus- 

 sion further data obtained from a subsequent study of stock derived from 

 cultures previously used (E. S. R., 3G, p. 523), states that the evidence ap- 

 pears conclusive tliat the actual conditions giving the various grades of self- 

 compatibility, and of self-incompatibility as well, are decidedly individual. Tlie 

 sporadic development of self-compatibility, giving self- fertility among the 

 progeny of self-sterile lines, is frequent in the cultures herein reported. Cyto- 

 logical studies are planned with regard to the questions of relative develop- 

 ment and nuclear phenomena in chicory. 



In case of physiological incompatibility, as in these cases, there is thought 

 to be no impotence except of a purely accidental sort. Any recombination may 

 survive. The evidence does not indicate selective or preferential matings, 

 favoring fusion between particular recombinations of germ plasm with resi)ect 

 to hereditary characters. The sporadic variability of the sex relations and 

 their fluctuating inheritance is emphasized. A number of possibilities are 

 suggested. 



Inheritance of endosperm color in maize, O. E. White {Amer: Jour. Hot., 

 k (1917), No. 7, pp. 396-406).— The author gives particulars of studies of 

 crosses of a variety of maize having yellow endosi^ei'm with one having white 

 endosperm, giving white only in Fj and approximately 3 white to 1 yellow 

 in Fs, with further results. Some of these are interpreted as due mainly to the 

 presence or absence of an endosperm color suppression factor. He claims that, 

 including the one mentioned, there are at least three and possibly five pairs 

 of factors concerned In the determination of endosperm color in maize. 



Inheritance studies in Pisum. — IV, Interrelation of the genetic factors of 

 Pisum, O. E. White (U. S. Dept. Agr., Jour. Agr. Research, 11 {1917), No. 4, 

 pp. 167-190). — This paper describes and discusses the number of demonstrated 

 factors in I'isum, their modifying effects upon each other's expression, the 

 modification of their expression by dift'erent environments, and their relation 

 to one another in inheritance, whether independent or linked. 



Thirty-five genetic factors are listed and discussed. The presence and ab- 

 sence of these 35 factors are said to be resijonsiblc for 70 or more differential 

 characters. The modifying effects of the expression of one factor upon another 

 and the 2ffects of external environmental conditions upon the expression of 

 these factors are described. Data involving many thousand Fz generation 

 progeny indicate that certain factors are independently inherited, that is, they 

 are not linked, unless the linkage is very loose. Data for four linked groups 

 are presented, three of which involve some of the factors mentioned above and 

 one the relations of which to the other seven are still undetermined. 



FIELD CROPS. 



Factors influencing the water requirements of plants, G. C. Thom and 

 H. F. Holtz (Washington Sia. Bui. l.',6 (1917), pp. 3-64, fiys. i8).— This reports 

 extensive investigations of the various factors inlluencing the water require- 



