190 GENETICS [Bot. Absts., Vol. V, 



1442. Anonymous. A supposed sheep-goat hybrid. Jour. Heredity 10: 357-359. 2 fig. 

 Nov., 1919. 



1443. Anonymous. Carriers of the germ plasm. Jour. Heredity 10: 422. Fig. 21. Dec, 

 1919. 



1444. Anonymous. To increase the birth rate. Jour. Heredity 11: 64. Feb., 1920. 



1445. Anonymous. An award of honor to Walter Van Fleet. Jour. Heredity 11: 95-96. 

 1 fig. Feb., 1920. 



1446. Anonymous. The death of Richard Semon. Jour. Heredity 11: 78-79. Feb., 1920. 



1447. Anonymous. Systematic breeding. Florists' Exchange 49: 986. April 24, 1920. — 

 Popular discussion of breeding, with remarks on the importance of the F2 generation in 

 crossing work. Breeding problems of the carnation, rose, cyclamen and sweet pea are 

 discussed. — Orland E. White. 



144S. Anonymous. Historia de los metodos de seleccion. [History of the methods of 

 selection.] Jalisco Rural [Mexico] 2: 7-8. 1919.— Popular. 



1449. Anthony, Stephen, and Harry V. Harlan. Germination of barley pollen. Jour. 

 Agric. lies. 18: 525-536. 2 pi., 2 fig. Feb. 16, 1920.— Experiments with barley pollen were 

 carried on: (1) with solutions, (2) with moist chambers, (3) fertilization in the field, (4) 

 retention of viability in the laboratory, (a) when pollen is left in free air; (b) when pollen 

 is kept over sulphuric acid; and (c) when pollen is kept in vacuo. No germinations were 

 secured either with water or solutions of sugar, agar, or nutritive substances of various osmotic 

 concentrations. Germination was finally obtained as follows: A slide containing pollen was 

 placed inside a Van Tieghem cell; a piece of mesophyll from a leaf of garden pea was placed 

 in the cell to supply water; the cell was covered with cover glass and placed outside on window 

 ledge. Germination was thus obtained in five minutes. In field experiments receptivity of 

 stigma and duration of viability of pollen were studied and results compared with those of 

 laboratory experiments. Extreme delicacy of water adjustment is the most noticeable 

 response of the pollen to treatment given in the experiments. Literature is reviewed. [See 

 also Bot, Absts. 5, Entry 949.]— W. E. Bryan. 



1450. Babcock, E. B. Crepis — a promising genus for genetic investigations. Amer. Nat, 

 54: 270-276. May-June, 1920. — It is desirable to find a genus with several crossable species, 

 whose chromosome numbers are low and different; linkage groups corresponding to the 

 chromosomes of each species should be understood. Crepis has 200 widely scattered and 

 diversified species. Of these one is already known to have 3 chromosome pairs, 6 or 7 have 4, 

 4 have 5, one has 8, one has 9, and one has 20. Cytologically these are unusually favorable 

 objects of study. Crepis is prolific, usually self-fertile, gives 2 or 3 generations a year, and 

 probably its species are crossable. Disadvantage is smallness'of flowers, making hybridiza- 

 tion tedious though not impossible. Author has already commenced work on two species 

 virens and tectorum, and urges other investigators to join in the attack, since an enormous 

 mass of data will be necessary before the desired goal is reached.— Merle C. Coulter. 



1451. Bancroft, Wilder D. [Rev. of: Jaeger, F. M. Lectures on the principles of 

 symmetry. 16x27 cm. xii + 333 p. Elsevier Publ. Co.: Amsterdam, 1917.] Jour. Phys. 

 Chem. 23 : 516. 1919. — The book deals with the principles of symmetry in chemical substances, 

 animals and plants. "While not easy reading, the book is an instructive one and contains 

 a great deal that is of interest" to all morphologists, especially those in botany who are also 

 interested in evolution. — H. E. Pulling. 



1452. Banta, Arthur M. Sex and sex intergrades in Cladocera. Proc. Nation. Acad. 

 Sci. [U. S. A.] 4: 373-379. Dec, 1918. — Certain species of Cladocera, as Daphnia pulex, Simo- 



