120 GENETICS [BoT. Absts., Vol. IX, 



partial impotence of the plant as a whole. The impotence of individual spores and gametes 

 is hence considered to be independent of their own composition. The grade of impotence is 

 assumed to be determined for the zygote as an individual, and the association of a lesser or 

 greater number of pairs of complementary genes decreases or increases the impotence. — 

 Hester M. Rusk. 



754. Malinowski, Edmund. Studya nad Mieszancami Pszenicy. [Studies on wheat 

 hybrids.] Prace Towarzystwa Naukowego Warszawskiego 30. 220 p., 10 pi., 33 fig. 1918. 

 [Polish, with French translation.] — A study of crosses of lax, squarehead, and compact types 

 of Triticum vulgare, with lax, square, and semicompact types of T. dicoccum. Seventeen 

 crosses are described as to their behavior in Fi and F2. Ninety-six selected F2 progenies are 

 described in the F3. Aside from the parental types, other forms appeared in the F2, — Triti- 

 cum spelta, T. turgidum, T. durum, some very similar to T. polonicum, and 2 new forms, T. 

 ellipsicum and T. lanceolatum. All these forms are distinguishable by the shape and size of 

 their glumes and spikelets. The author attributes the size and shape of the glimies and spike- 

 lets to the presence or absence of cumulative factors. Size and shape of grain are related to 

 the size and shape of the glume. Partial or complete sterility is explained on the basis of 

 Mendelism through 2 or more discordant factors meeting in the same individual. The degree 

 of sterility depends on the number as well as the quality of these factors. Three types of 

 inheritance are obtained as regards length of head, giving ratios of 1 : 2 : 1, 3 : 1, and 15 : 1. 

 These are found by intercrossing to be related and the factors concerned are complementary. — 

 R. Summerby. 



755. Marie-Victorin, Fr. La vie sexuelle chez les Hydrocharitacees. [The sexual life 

 of the Hydrocharitaceae.] Nat. Canadien 45: 130-133. 1919. — The method of pollination in 

 Vallisneria is discussed, comparing the statements of Mignault [see Bot. Absts. 3, Entry 

 1112] with the generally accepted ideas. The author describes the liberation and opening 

 of the staminate flowers of Philonotria canadensis (Michx.) Britton {Elodea canadensis Michx.) 

 and the opening and pollination of the pistillate flowers, his observations agreeing essentially 

 with those of Wylie (The morphology of Elodea canadensis. Bot. Gaz. 37: 1-22. 1904). 

 [See also Bot. Absts. 3, Entry 1111.]— C. E. Allen. 



756. Morgan, T. H. Variation in juvenile fiddler crabs. Amer. Nat. 55:82-83. 1921.— 

 The author replies to Miss Rathbun's criticism [see Bot. Absts. 9, Entry 759] of his former 

 paper (Amer. Nat. 54: 220-240). He states that these "small crabs with narrow abdomen 

 were stated in my paper to show either a change toward maleness or possibly a retention of 

 the juvenile condition," that out of more than 3000 individuals that were collected only a few 

 showed the narrow abdomen, and that with considerable reservations he had ventured to 

 call these intersexes because the variation in question was in the direction of a character 

 peculiar to the opposite sex. — A. M. Banta. 



lb" . Northrop, John H. Concerning the hereditary adaptation of organisms to higher 

 temperature. Studies Rockefeller Inst. Med. Res. 36: 259-2G4. 1921. — Reprinted from Jour. 

 Gen. Physiol. 2: 313-318. 1920 [see Bot. Absts. 5, Entry 433].— Geo. H. Shull. 



758. P[openoe], P[atjl]. [Rev. of: Gritenberg, Benjamin C. Elementary biology. 

 X + 528 p., 26 fig. Ginn & Co. : Boston, 1919 (see Bot. Absts. 3, Entry 1902).] Jour. Heredity 

 12:41. 1921. 



759. Rathbun, Mary J. On intersexes in fiddler crabs. Amer. Nat. 55: 80-82. 1921. — 

 The author criticizes Morgan's interpretation of exceptional fiddler crabs as intersexes 

 rather than juvenile states, asserting that he has " . . . . thereby seemingly robbed 

 the female fiddler of its period of adolescence." [See also Bot. Absts. 9, Entry 756.] — A. M. 

 Banta. 



