1917] FIELD CROPS. 131 



New dimorphic mutants of the CEnotheras, H. DeVkies {Bot. Gas., 62 

 {1916) y No. 4, pp. 249-280, figs. 5). — A study has been made of the genetic be- 

 havior of CB. scintillans, GE. cana, CE. pallescens, CE. lactuca, and (E. Hquida, 

 mutants of CE. lamarckiana. Each of these in every generation, under or- 

 dinary circumstances, splits into nearly equal groups of the mutant type and 

 of the parent type, the CE. lamarckiana offspring being nearly constant in their 

 progeny. Besides the two main types each usually produces a relatively high 

 peroeutage of other mutants. The parental types appear on an average in 

 about 40 per cent (on very strong biennials as much as 97 per cent), the 

 other 60 per cent (or less) being CE. lamarckiana mutants, these figures vary- 

 ing with cultures or with individuals. Dimorphic mutants of this type also 

 occur in allied species of the biennis group. In dimorphic mutants the special 

 characters are inherited through the ovules, but not, so far as known, through 

 the pollen, which appears like that of pure CE. lamarckiana. 



The dimorphic mutants constitute a group in which the hereditary phe- 

 nomena are evidently independent of the external visible characters of the 

 special members of the group, but are assumed to have the same intrinsic 

 causes in the different cases. 



Sterility as the result of hybridization and the condition of pollen in 

 Rubus, C. S. Hoar {Bot. Gas., 62 {1916), No. 5, pp. S70-388, pis. 3).— The author 

 gives a brief review of previous work and information regarding pollen sterility 

 and related phenomena, witli an account of work done by himself in 1915 on 

 some 40 species of Rubus, from which mature pollen grains were obtained 

 for utilization in study by a method which is described. He also details the 

 percentages obtained of pollen found to be sterile in different degrees in many 

 of the species. 



It is stated that pollen sterility is a common character throughout the entire 

 genus. This is thought to typify a condition prevailing in many angiosperms, 

 among which are found many forms appearing as natural hybrids between 

 distinct species and exhibiting more or less blending of characters rather than 

 Mendelian segregation. Rubus hybrids formed between distinct species are 

 almost entirely sterile, while crosses of closely related and supposedly more 

 compatible varieties may give almost no indication of a hybrid origin. 



FIELD CROPS. 



Report of the agronomy division, C. A. Sahr {Hawaii Sta. Rpt. 1916, pp. 

 26-31, pis. 2). — This reports a continuation of work previously noted (E. S. R., 

 35, p. 527). 



The 1916 spring rice crop on the nonaerated plat fell 51 per cent below the 

 yield of the same plat in 1915, but outyielded the aerated plat by 490 lbs. of 

 rice paddy, or 18.7 per cent. 



Early Rose outyielded Burbank and American Wonder in potato variety 

 tests at the Tantalus substation (elevation 1,000 ft.). In culinary tests of 

 these varieties the Burbank proved superior in mealiness and flavor. 



Cultural trials of Phaseolus aconitifolius, Crotalaria candicans, Desmodium 

 hirtum, and several clovers are briefly noted. The average yields of green 

 forage per acre for the red clovers were as follows : Red clover from Switzer- 

 land (S. P. I. No. 37939) 8.55 tons, ordinary red clover (F. C. I. No. 1472) 

 8.45, Swiss Rummellee clover or apitrefle (S. P. I. No. 37937) 2.1, and red 

 clover from Switzerland (S. P. I. No. 37938) 1.8 tons, Alsike clover gave a 

 yield of 6.15 tons per acre. Ordinary white clover (S. P. I. No. 34930) made 

 appreciably more growth than wild white (S. P. I. No. 38579) and Ladino 



