102 GENETICS [Bot. Absts., Vol. IV, 



Triticum durum, T. turgidum, and . T. polonicum, female plants with 14-28 chromosomes 

 with T. vulgare, T. compactum, and T. spelta, with 21-42 chromosomes, Fi root tips gave uni- 

 formly 35 chromosomes. The prophase is apparently of the usual type, bivalent chromosomes 

 probably arising by the formation of post-synaptic loops. Heterotypic metaphase shows 14 

 bivalent and 7 univalent chromosomes. The 14 pairs separate and the 7 singles split longi- 

 tudinally, giving 21 at each pole. In the second division the 14 undergo the usual equational 

 split but the 7 are distributed somewhat tardily to one pole or the other or occasionally one 

 or more left out of the daughter nuclei. Pollen nuclei thus contain 14 + x (x = to 7) chro- 

 mosomes with 17 or 18 most usual. Excluded chromosomes form chromatin nucleoli, which 

 degenerate before maturity of the pollen. Of 5 F 2 plants 4 showed 38 and one 35 chromo- 

 somes in somatic mitoses. One F4 plant showed a single preparation with five figures, each 

 showing clearly 41 chromosomes. Somatic counts in a wheat-rye hybrid of the fifth genera- 

 tion (back-crossed to the wheat) gave counts of 42 like the Fi in some cases but of only 38 in 

 other plants grown from seed from the same ear as the first. The author promises to attempt 

 to discover the relation of these cytological facts to the breeding behavior of these most inter- 

 esting hybrids. — Leonas L. Burlingame. 



628. Kihara, Hitoshi. Ueber cytologische Studien bei Getreidearten. Mitteilung II. 

 Chromosomenzahlen und Verwandtschaftsverhaltnisse unter Avena-arten. [Cytological 

 studies in the cereals. II. Chromosome counts in reference to the relationship of oat species.] 

 Bot, Mag. Tokyo 33: 94-97. 2 fig. 1919.— See Bot. Absts. 3, Entry 1939. 



629. Killer, J. Uber die Umziichtung reiner Linien von Winterweizen in Sommerweizen* 

 [Concerning the changing over of pure lines of winter wheat into spring wheat.] Jour. Landw. 

 67: 59-62. 1919.— See Bot. Absts. 4, Entry 87. 



630. King, Helen D. Studies on inbreeding. IV. A further study of the effects of in- 

 breeding on the growth and variability in the body weight of the albino rat. Jour. Exp. Zool. 

 29: 71-111. 8 fig. Aug. 20, 1919. — Presents data on the growth curves and variability of two 

 strains of albino rats in the 16th to 25th generation of brother-sister mating, together with 

 similar data for a control stock. All stocks showed a reduction from previous years in rate of 

 growth and maximum weight, due wholly, it is believed, to unfavorable environmental condi- 

 tions. The inbreds continue to be heavier than controls of the same age raised under the 

 same conditions. There is no indication that inbreeding has caused a change in the form 

 of the growth curve or the relative weights of the sexes. Growth curves for two independent 

 inbred lines are nearly identical. As before, the coefficient of variation for the weight in- 

 creases up to 60 days, decreases to three hundred days and then increases as some of the 

 rats begin to fatten. Males as usual are more variable than females. Inbreds remain less 

 variable than controls, but are more variable than earlier inbreds. Similar increase in varia- 

 bility of controls indicates that environmental conditions are responsible. — Sewall Wright. 



631. Klatt, B. [Rev. of: Steche, O. Grundriss der Zoologie. (Foundation of zoology.) 

 508 p. Veit. u. Co. : Leipzig. 1919.] Zeitschr. indukt. Abstamm. Vererb. 22:53-55. Dec., 

 1919. 



632. Klatt, B. [Rev. of: Stieve, H. Uber experimentell, durch veranderte aussere 

 Bedingungen hervorgerufene Ruckbildungsvorgange am Eierstock des Haushuhnes (Gallus 

 domesticus). (On reversional processes in domestic fowl produced experimentally by changed 

 external conditions.) Arch. Entwicklungsmech. 44: 1918.] Zeitschr. indukt. Abstamm. 

 Vererb. 22 : 57-58. Dec, 1919. 



633. Klatt, Berthold. Keimdrusentransplantationen beim Schwammspinner. Ein 

 experimenteller Beitrag zur Frage der Vererbbarkeit erworbener Eigenschaften. [Germ-cell 

 transplantation in Lymantria. An experimental contribution to the question of inheritance of 

 acquired characters.] Zeitschr. indukt. Abstamm. Vererb. 22:1-50. Dec, 1919. 



