June, 19201 GENETICS 319 



2141. HOOPER, C. H. The pollination of fruit in relation to commercial fruit growing. 

 British Bee Jour. 46 (1463): 13, L4. Ibid. 46 (1465):28, 29. Ibid. 46 (1467):45. Ibid. 46 



(1470): 7;?. Ibid. 46 (1471): 79, SO. Ibid.46 (1473): 07,98. 1918.— This is mainly a summary of 

 English work, including the experiments of the author. Most clones of apple produce more 

 fruit if pollinated from another clone. Only 24 among several hundred are regarded as more 

 or less self-fertile. The majority of pear clones are self-fertile. Six in England and 6 in 

 America are noted as being slightly self-fertile. Some of the selfed fruits were seedless and 

 cucumber-shaped. Plum clones are about equally divided between the; self-sterile and the 

 partially or wholly self-fertile. Only two are named which set fruit nearly as well when 

 selfed as when cross-pollinated. The damsons are more or less self-fertile. Most of the cherry 

 clones are self-fertile. Morello and Late Duke are self-fertile. Cherry clones are more 

 inter-sterile than other fruits. Clones of gooseberry; white, red, and black currants; logan- 

 berry; and perfect-flowered strawberry; do not show self-sterility.— John Belling. 



2142. Johnson, James. The inheritance of branching habit in tobacco. Genetics 4: 

 307-340. 8 pi.. 2 fig. July, 1919.— Inheritance of suckcring habit has been studied in cross 

 between Little Dutch, which produces few suckers, and Cuban, which produces many large 

 suckers. Parents and several generations of cross were grown same year. Reciprocal crosses 

 were alike in F,, being intermediate in sucker number but slightly higher in weight of suckers. 

 Range of the F 2 is as great as combined range of parents. Segregation is definitely shown in 

 F 3 and later generations. Strains were isolated which were suckerless like Little Dutch parent 

 and others which approach suckering habit of Cuban parent. Certain of these were no 

 more variable than the parental types as shown by standard deviation (5). Segregation 

 occurred for other characters, such as height of plant, number of nodes and leaves, size and 

 shape of leaves. Two abnormalities were obtained. No correlation appears to exist between 

 number, size and shape of leaves and suckering habit. Results are interpreted on the mul- 

 tiple factor hypothesis which has been formerly used for interpreting inheritance of quanti- 

 tative characters. — H . K. Hayes. 



2143. Jones, D. F. Selection of pseudo-starchy endosperm in maize. Genetics 4:364- 

 393. 8 pi., 1 diagram. July, 1919.— Analysis of an apparently intermediate endosperm char- 

 acter in maize is presented. This intermediate condition between true starchy and sugary 

 endosperm is termed pseudo-starchy, resembling the typical starchy maize in gross chemical 

 analysis but approaching the sweet type in nature of the starch grains and texture of endo- 

 sperm. — Selection experiments upon this endosperm character for 10 years were successful 

 in producing as end results a typical starchy-appearing strain and a true sweet strain. Selec- 

 tion was not markedly effective in the first generation but during the following four generations 

 the divergence between the two end types was completed. — Reciprocal crosses of this selected 

 starchy (pseudo-starchy) strain and true starchy plants gave a starchy Fi and a definite F 2 

 segregation of 3 starchy to 1 sweet. The appearance of the pseudo-starchy endosperm in F 2 

 as sweet endosperm indicates a genetic difference between pseudo- and true starchiness.— 

 Reciprocal crosses between the end products of the selection experiments showed no immedi- 

 ate effect on the endosperm. This fact, coupled with the intermediate and variable nature 

 of the Fi ears as regards endosperm characters, and the occurrence in subsequent generations 

 of a distinct 3: 1 and 1: 1 segregation of endosperm, suggest the presence of a plant factor 

 governing endosperm expression and two endosperm factor-pairs. — The results of selection 

 are explained as being due to the sorting-out and rearrangement of such factors and not to 

 the progressive change of an intermediate and incompletely segregating genetic factor. — 

 E. W. Lind slrom. 



2144. Jones, D. F., and C. A. Gallastegui. Some factor relations in maize with refer- 

 ence to linkage. Amer. Nat. 53:239-246. May-June, 1919.— Authors present data in con- 

 firmation of results of Collins that ordinary pod (tunicate) corn is heterozygous always throw- 

 ing normal, heterozygous tunicate, and nearly sterile homozygous tunicate. They report 

 discovery of linkage between factors for tunicate ear and sugary endosperm with 8.3 per cent 



BOTANICAL ABSTRACTS, VOL. Ill, NO. 6 



