PROCEEDINGS OF THE ACADEMY AND AFFILIATED 



SOCIETIES 



BOTANICAL SOCIETY OF WASHINGTON 



The 106th regular meeting of the Botanical Society of Washington 

 was held at the Cosmos Club, Tuesday, October 5, 1915, at 8 p.m. 

 Thirty members and two guests were present. The following scientific 

 program was given: 



Some recent investigations in sugar-beet breeding (lantern slides) : 

 F. J. Pritchard. The speaker presented a large number of tables and 

 figures based upon 10 years' experiments in sugar-beet breeding from 

 which the following conclusions were drawn: Differences in the size, 

 total sugar content, and percentage of sugar of individual beet roots 

 show no evidence of inheritance. There is no correlation between 

 percentage or quantity of sugar of roots of ordinary sizes and their 

 yield of seed nor between their yield of seed and the average percentage 

 of sugar in their progeny. Fluctuations in percentage and yield of 

 sugar of beet families planted in progeny rows in alternation with check 

 rows greatly exceed their real differences. The discontinuance of selec- 

 tion for one generation caused no deterioration but some apparent 

 gain in percentage of sugar. No improvement was obtained in yield 

 or percentage of .sugar from continuous selection ; both the good and 

 the poor families transmitted average qualities. Fluctuations in per- 

 centage and yield of sugar are caused chiefly by irregularities of the 

 soil; the nutritive conditions which favor the production of a large 

 root cause a large tonnage of beets but a low percentage of sugar; even 

 with a uniform stand certain rows and certain parts of the field produce 

 a relatively small root and consequently a high percentage of sugar, 

 while neighboring areas produce a large root and a low percentage of 

 sugar. As the fluctuations in percentage and yield of sugar are large 

 they obscure real differences between varieties or families, but real 

 differences may be distinguished by planting each variety or family 

 a large number of times. 



Notes on plant-parasitic ne?natodcs (lantern slides) : L. P. Byars. 

 After a few introductory remarks concerning the general characteristics 

 of the three groups of nematodes — the free living, animal-parasitic, 

 and plant-parasitic — the speaker indicated some of the more important 

 anatomical and life-history features of species belonging to the last 

 group. Emphasis was laid on the economic importance of and present 

 distribution of Tylenchus dipsaci, the bulb and stem-infesting nematode; 

 Tylenchus tritici, a nematode living in wheat kernels; Aphelenchus 

 armerodis, the violet bud organism; and Heterodera radicicola, the 

 gall-forming nematode, all of which are parasites introduced into this 

 country. Illustrations and drawings were used to show the speaker's 



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