March, 1920] GENETICS ( .Jl 



Early freestones and semi-clings give about 10 per cent from stone to tree, later freestones 

 give, up to 50 per cent. — Total of 403 trees of known parentage were planted in spring of 191G, 

 and 1073, in 1917. No method is yet devised to [secure Fi generation. [See Bot. Absts. 2, 

 Entry 724.]— C. E. Myers. 



609. Coulter, Merle C. Inheritance in Pediastrum. [Rev. of: Harper. R. A, 

 Organization, reproduction, and inheritance in Pediastrum. Proc. Amer. Phil. Soc. 66: 375-439. 

 PL 6-6, fig. 64. 1918.] Bot. Gaz. 67:513-514. June, 1919.— Many complexities occur in 

 reproductive processes of flowering plants, and reviewer conceives that studies on lower 

 organisms promise to have profound bearing on theoretical genetics. He thinks however that 

 the peculiarities of Pediastrum make doubtful the applicability of author's conclusions to 

 higher plants, though he sees that there may be something comparable between the method 

 of colony formation in Pediastrum and the arrangement of nuclei in early stage of embryo 

 formation in gymnosperms and arrangement of nuclei in the embryo-sac of angiosperms. — 

 G. H. Skull. 



610. Coulter, Merle C. Mendelian inheritance in gametophytes. [Rev. of: Transeau, 

 Edgar Nelson. Hybrids among species of Spirogyra. Amer. Nat. 53:109-119. Fig. 7. 

 1919. (See Bot. Absts. 2, Entry 715.)] Bot. Gaz. 67: 514-515. June, 1919.— Reviewer consid- 

 ers behavior of gametophyte generation one of most critical tests of current theoretical mech- 

 anism of inheritance, and thinks the lower plants especially favorable material for such stud- 

 ies. Predicts that segregation will be found taking place in the first generation and there 

 should be no dominance. Transeau's studies were purely observational but are taken to agree 

 with this expectation. Reviewer hopes that the author will find means of studying the hybrid 

 Spyrogyras "under rigid experimental control." — G. H. Shull. 



611. Coulter, Merle C. A corn pollinator. Bot. Gaz. 68: 63-64. 1 fig. July, 1919.— 

 See Bot. Absts/3, Entry 989. 



612. Coulter, Merle C. A new conception of sex. [Rev. of: Jones, W. N. On 

 the nature of fertilization and sex. New Phytol. 17: 167-188. 1918.] Bot. Gaz. 68:68-69. 

 July, 1919. 



613. Coulter, Merle C. Self-sterility. [Rev. of: East, E. M., and J. B. Park. Stu- 

 dies on self-sterile plants. II. Pollen-tube growth. Genetics 3 : 353-366. 8 fig. 1918.] Bot. 

 Gaz. 68:70-71. July, 1919. 



614. Cowgill, H. B. Cross-pollination of sugar cane. Jour. Amer. Soc. Agron. 10: 302- 

 306. 1919— See bot. Absts. 3, Entry 2106. 



615. Cowgill, H. B. Studies in inheritance in sugar cane. Jour. Dept. Agric. Porto 

 Rico 2: 33^1. 1918— See Bot, Absts. 3, Entry 2107. 



616. Dahlgren, K. V. Ossian. Erblichkeitsversuche mit einer dekandrischen Capsella 

 bursa-pastoris (L.) [Genetical experiments with a decandrous Capsella bursa-pastoris.] 

 Svensk. Bot. Tidsskr. 13 1 : 48-60. 2 fig. 1919.— The author relates some results obtained 

 by crossing a constant type of Capsella bursa-pastoris having petals transformed into sta- 

 mens, with Capsella Heegeri and two of Almquist's "elementary species" of C. bursa-pastoris 

 (viz., C. collina and C. emarginata) . — Apetalous forms are not a uniform race. The apetaly 

 can be produced either by abortion of the petals or by their transformation into stamens. By 

 unfavorable nourishment petals and stamens sometimes disappear and i eal female flowers 

 (fertile) may be obtained. — In Fi the apetalous type prevails, but small petals or intermedi- 

 ate forms between petals and stamens are seen. In F 2 segregation takes place according to 

 the proportion 3 : 1, if we consider apetalous individuals (EE) and heterozygotes (Ee) as one 

 group. These two categories are rather difficult to separate. In some families the number 

 of individuals with petals was too great. This might be caused by foreign seeds in the soil. — 



