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



probably with B only, rose-lilac. (2) In G. Whitneyi it was shown that aa plants have smaller 

 corollas, though it is probable that other genes are also concerned in corolla length. (3) 

 Segregation was shown in this species, but the factors were not definitely determined for light 

 and dark green leaves, long narrow versus short broad leaves, and low dense growth habit 

 versus taller lax type. The latter is probably a simple genetic difference due to gene R. (4) 

 Linkage relations suggest that the B, E, and G allelomorphic pairs are in the same chromosome 

 pair. The crossover percentage for the B and E pair was figured at 14.3 per cent. C and F 

 genes are thought also to be linked but in a 2nd chromosome pair. (5) In G. amoena a pure 

 variety was found with a large spot on the petals not reaching to the base ("Querfleck"), 

 and another with a small basal spot. Types with both spots when self ed gave 1 "querfleck:" 

 2 double-spot: 1 basal spot. Both types of spots give 3:1 ratio with unspotted Whitneyi 

 varieties. The author suggests either multiple allelomorphism or close linkage, preferring 

 for the present the latter. (6) Double is dominant to single (gene U) but is influenced in 

 G. amoena by factor L ox K concerned with spotting. Basal-spot flowers {Lg Lg) are more 

 double than double-spotted ones (Lg IG) and these more double than "querfleck" {IG IG). 

 (7) No Oenothera-li^e phenomena were found and interspecific crosses behaved like varietal 

 ones in respect to flower color, doubleness of flower, and growth form of plant, at least in so 

 far as the small progenies permit a decision. — Leonas L. Burlingame. 



1367. Rasmuson, Hans. On some hybridization experiments with varieties of Collinsia 

 species. Hereditas 1 : 178-185. 1 fig. 1920. — A white-flowered variety of Collinsia bicolor 

 was crossed Vv^th the normal type having lilac on the under lip and being whitish on the upper. 

 Fi plants were lilac, and in F2 segregation of 9 lilac to 7 white was observed. Green stem was 

 recessive to red, and the F2 ratio was approximately 9 red : 3 slightlj' tinged with red : 4 green. 

 An A factor is assumed which produces white flowers and red-tinged stem, and a B factor 

 which causes white flowers and green stem. AB gives lilac flowers and red stem, and ab 

 gives white flowers and green stem. A variegated plant of C. tincioria crossed with the self- 

 colored type gave 3 self to 1 variegated in F2. One-fourth of the variegated plants were yellow 

 and non-viable. A gene, I, is postulated which increases the amount of green in variegated 

 plants. The yellow plants are assumed to be ii. Spots on the upper lip of the flower of 

 C. tinctoria proved to be a simple Mendelian dominant condition. — A. C. Eraser. 



1368. Ratjm. Weissbliihender Rotklee eine umschlagende Sippe?" [White-fiowering 

 red clover, an "ever-sporting variety?"] Zeitschr. Pflanzenziicht. 8: 73-77. 1921. — Seeds 

 of open-pollinated white-flowering heads of red clover produced 0.8 per cent white-flowering 

 plants, presumed to have arisen through geitonogamy, produced seed unguarded but geograph- 

 ically isolated. Of 200 offspring only 11, or 5 per cent, came white. Seed from 48 red- 

 flowered plants descended from white-flowered plants produced white-flowered plants in only 

 19 of the 48 families to the extent of 41 white to 231 red. Some intermediacy was evidenced 

 by flower color. The author believes that the data warrant the conclusion that white-flower- 

 mg red clover is an ever-sporting form comparable in some ways to four- and five-leaved 

 ever-sporting strains of red clover. The problem is considered of economic importance. [See 

 also Bot. Absts. 9, Entry 1329.]— L. R. Waldron. 



1369. Regan, W. M. Breeding experiments with dairy cattle. New Jersey Dept. Agric. 

 Bull. 24. 323-326. 1920. — The author describes breeding experiments now in progress, the 

 object of which is to determine the value of inbreeding, line-breeding, and out-breeding in 

 improving dairy cattle. It is also planned to attack the questions of "nicking" and inheri- 

 tance of milk secretion. — E. Roberts. 



1370. Rhodes, Robert Clinton. Binary fission in Collodictyon triciliatum Carter. 

 Univ. California Publ. Zool. 19: 201-274. PI. 7-U, 4 fig. 1919.— The author presents a 

 detailed account of Collodictyon triciliatum, free-living flagellate reproducing solely bj' binary 

 fission. An extended discussion is given of its affinities based on the form of mitosis, of which 

 full descriptive account is given. — R. E. Clausen. 



