200 GENETICS [Bor. Absts., Vol. V, 



1514. Grantham, J., and M. D. Knapp. Field experiments with Hevea. Agric. Bull. 

 Federated Malay States 6: 595-597. 1918. 



1515. Grantham, J., and M. D. Knapp. Field experiments with Hevea. Arch. Rubber- 

 cultuur 2 : 614-630. 1918. 



1516. Green, Heber. The application of statistical methods to the selection of wheat for 

 prolificacy. Agricultural research in Australia. Advisory Council Sci. and Ind. Common- 

 wealth of Australia Bull. 7: 49-56. 1918. — Author discusses application of familiar biometric 

 methods and points out their limitations in wheat breeding. Experiments have been con- 

 ducted for seven generations in selecting the heavy-, medium-, and light-yielding plants of 

 wheat. Progress in both directions resulted, though apparently mucii more rapid, m the 

 direction of high yield. — In an attempt to develop a wheat suitable for semi-arid climates an 

 unusually severe season destroyed all but three plants in a plot. One of these three was a 

 giant, the progeny of which has given rise to a valuable strain. — J. H. Kevipton. 



1517. Haecker, V. Eine medizinische Formulierung der entwicklungsgeschichtlichen 

 Vererbungsregel. [A medical formulation of the developmental law of heredity.] Deutsch. 

 Med. Wochenschr. 44: 124-126. 1919.— The author's "developmental law of heredity" [See 

 Bot. Absts. 4, Entry 588] is briefly explained and illustrated. In general the clearness with 

 which a trait segregates in heredity is a function of the autonomy of that trait in development. 

 Hereditary defects occurring in organs with a higti degree of developmental autonomy tend 

 to follow simple Mendelian rules in heredity while those dependent for their manifestation 

 on disharmonies in several organs or systems (e.g., diabetes) do not do so. Cases in which the 

 same organ shows different defects in various members of the same family are interpreted as 

 indicating an early autonomy of the organ in question with a more or less generalized weak- 

 ness of that organ in the particular family concerned. — C. H. Danforth. 



1518. Harlow, H. V., and H. K. Hates. Breeding small grains in Minnesota, n. 

 Investigations in barley breeding. Minnesota Agric. Exp. Sta. Bull. 182: 45-56. 4 fig. Mar., 

 1919. — Two lines of investigation (pure-line and hybridization) are discussed as methods of 

 barley improvement. From selections of domestic and foreign sorts it was found that almost 

 as wide variations in yield were found within a variety as in different varieties. By means of 

 several crosses between Lion, a smooth-awned black barley, and Manchuria, a smooth-awned 

 barley of high yielding ability has been produced. Other promising crosses have also been 

 obtained. Sixty-eight selections, crosses and new introductions are compared on the basis 

 of the yearly production. A method for discarding in elimination tests based on the probable 

 error is presented. — W. E. Bryan. 



1519. Harper, R. A. Inheritance of sugar and starch characters in corn. Bull. Torrey 

 Bot. Club 47: 137-186. 3 pi. April, 1920.— Work of Correns and of East and others on 

 the inheritance of sugar and starch characters in corn endosperm (Zea) is reviewed to show that 

 intermediate sweet-starchy types result from crossing these two forms. Original experiments 

 with crosses of different sweet and starchy endosperm varieties carried to the fourth filial 

 generation are described and illustrated. Dominance of starchiness is shown in first cross 

 but in segregating generations intermediate kernels ranging from practically pure sweet to 

 pure starchy in appearance were obtained in varying proportions and degree along with 

 other cases in which more definite segregation occurred. The different grades of kernels 

 are classified and tabulated. Marked tendency shown for intermediate types to breed true 

 but with more of an inclination to revert to sweet type than to starchy type. Practically 

 pure starchy ears, in appearance, were obtained from a cross of two sweet varieties. Con- 

 tinuity of variation in both sexually and asexually reproduced types is taken as an indication 

 of mutual modification of germplasm where contrasting characters are brought together. 

 The main features of chromosome individuality and of reduction phenomena are considered 

 as established but the physiological nature of the chromatin is thought to permit mixing of 

 hereditary materials resulting in intergradations between parental forms. — D. E. Jones. 



