274 GENETICS [BoT. Absts., Vol. VIII, 



spikes. The inheritance of this type is not completely solved as yet. From the appearance 

 and development of ears ending in staminate spikes and of ears borne as basal branches of 

 the terminal inflorescence (noted in a Hopi-brachytic cross), the author suggests "that the 

 ear of maize may have developed from the basal branches of the terminal panicle rather than 

 from the central spike of the terminal inflorescence of a lateral branch of the main culm." — 

 Many good illustrations are given of the types of maize under discussion. — E. W. Lindstrom. 



1924. Kempton, J. H. Linkage between brachytic culms and pericarp and cob color in 

 maize. Jour. Washington [D.C.] Acad. Sci. 11: 13-20. 1920. — Author summarizes genetic 

 linkages that have been reported for maize and describes a new case of linkage. Brachytic 

 {hr) maize, which is a dwarf type recessive to normal stature, is found to be linked with peri- 

 carp and cob color. Three crosses involving the normal-brachytic and colored-colorless 

 pericarp and cob factors give fairly large F2 distributions showing linkage relations that varied 

 from 35 to 38 per cent crossing over. — Data are presented from these F2 families that indicate 

 independent inheritance between brachytic culm and liguleless leaf as well as between cob 

 color and liguleless leaf. — E. W . Lindstrom. 



1925. KoTTUR, G. L. "Kumpta" cotton and its improvement. Mem. Dept. Agric. India 

 Bot. Ser. 10: 221-272. PL 1-7. 1920.— "Kumpta" is the trade name of a type of Gossypium 

 herbaceum extensively grown in India. Author demonstrated that the type comprises several 

 strains differing in number of vegetative branches, size and shape of leaves, length of bracts 

 and petals, size and shape of bolls, weight of seed, and length of fiber. A strain developed 

 by selection and decidedly superior to the average of the type in habit of growth, earliness, 

 productivity, and abundance and length of fiber is described. — T. H . Kearney. 



192G. Laughlin, Harry H. Calculating ancestral influence in man; a mathematical 

 measure of the facts of bisexual heredity. Genetics 5: 435-458. 2 pi., 1 fig. Sept., 1920. — 

 Twenty-five formulae governing ancestral inheritance in general are presented, based on: 

 (1) Bisexual reproduction; (2) heterozygosis for sex factor in one sex; and (3) the number of 

 pairs of chromosomes. Cognizance is taken of the necessity for increased accuracy by means 

 of future inclusion of provisions for sex-linked traits, relative weighting of chromosome groups, 

 maternal or paternal source of chromosome, dominance or recessiveness of gene, and relative 

 frequency of mutation, crossing-over, non-disjunction, and otherspecialchromosomephenom- 

 ena; but these are not considered in the formulae developed, since they would operate only 

 as special modifications of the general case. Figure 1 presents a clever mechanism for demon- 

 strating the segregation and recombination of chromosomes from ancestors to descendants, 

 "with specifications for its construction. Plate 1 diagrams ancestral inheritance in the human 

 <nale, based on 12 pairs of chromosomes, showing the "X-trails" and "Y trails" of descent 

 for the X and Y chromosomes, and calculates the average, range and chance of contribution 

 of chromosomes to the Fi zygote in P2, P3, and P, while plate 2 presents the same data for the 

 hulnan female, with suitable changes for sex. Similar constants for P4 and Ps are included 

 in notes accompanying the plates. — Edward N . Wentworth. 



1927. LiNEBACK, p. E. A case of unilateral Polydactyly in a 22-mm. embryo. Anat. 

 Rec. 20 : 313-319. 1 fig. Feb. 20, 1921 . — A 22 mm. human embryo was found to have an extra 

 digit on the radial side of the right hand. This is apparently the youngestpolydactylindivid- 

 ual thus far recorded. Unfortunately there is no information as to its parentage. Micro- 

 scopic study reveals all the usual cartilaginous elements of the hand present and normal. 

 In addition there is a single extra cartilage associated with the supernumerary digit. There 

 are two muscles extending into the extra digit, but no obvious nerves and only capillary blood 

 vessels. The specimen "offers proof that some cases of Polydactyly owe their origin to earlier 

 causes than external factors or deviation of ossification centers." The condition is believed 

 to be wholly distinct from hyperphalangy of the thiunb. — C. H . Danforth. 



1928. Little, C. C. Report of the Committee on Genetic Form and Nomenclature. Amer. 

 Nat. 55: 175-178. 1921. — This is the first report of a committee appointed in 1919 by the 



