34 Varietäten, Descenderiz, Hybriden, 



Other similar Systems secure greater brevity or clearness in 

 certain cases, but are usually of less general applicability ; the 

 main differences relate to the designation of series and their initial 

 individuals. 



This System provides for polyembryony and somatic Variation , 

 and permits of the addition of various other refinements in cases 

 where they may be needed. The basic scheme is perhaps as 

 simple and convenient as is consistent with use for all purposes 

 without change in essential features. 



In this and similar Systems, the numbers are eumulative; 

 Shull's noncumulative System has both advantages and disadvan- 

 tages in comparison. 



To summarize the most essential features of the proposed 

 method : 1. the series for a given plant (genus or species) are 

 numbered consecutively ; 2. the initial „individuals", as defined in 

 the records, are denoted by small letters, afifixed to the series 

 numbers; 3. in each foUowing generation the individuals are num- 

 bered (if sexual produced) or lettered (if asexually produced), an 

 afifixed letter indicating a particular part of an individual; 4. repro- 

 duction or propagation is always indicated by a dash; 5. capital 

 letters are employed for miscellaneous special uses. 



M. J. Sirks (Wageningen). 



Hance, R. T., An attempt to modify the germ plasm of 

 Oenothera through the germinating seed. (American 

 Naturalist. LI. p. 567-572. 1917.) 



Seeds and seedlings of Oenothera biennis L. (the Dutch hiennis 

 from a pedigreed line which has been inbred for at least eight 

 generations), were chosen as object for some experiments about 

 treatment of germ plasm with different Solutions (acetic acid, 

 butyric acid, chloralhydrate, chromic acid, ethyl alcohol, methylal- 

 cohol, amylic alcohol, butylic alcohol, propylic alcohol, zinc sul- 

 phate, strychnine, potassiumbromide and iodide, ferric alum.). The 

 material vras either thoroughly washed before being placed on 

 moist filter paper in petri dishes, to complete germination, or it 

 was placed on paper which had been moistened with the same 

 Solution as that in which the material had been soaked. 



In general it may be said that the treatment of seeds and 

 seedlings in the experiments has resulted, as in the experiments 

 of üthers, in reducing the percentage of germination or in a general 

 weakening of the plants rather than in specifically modifying the 

 germinal Constitution. The results from the experiments with chro- 

 mic acid and possibly with chloral hydrate and ethyl alcohol 

 suggest the desirability of further studies. In future work the 

 concentration of the agent and the length of treatment should be 

 studied in greater detail. M. J. Sirks (Wageningen). 



Jemntings, H. S., Modifying factors and multiple allelo- 

 morphs in relation to the results of selection. (American 

 Naturalist. LI. p. 301—306. 1917.) 



It appears to the writer that the work in Mendelism, and 

 particularly the work on Drosophila, is supplying a complete foun- 

 dation for evolution through the accumulation by selections of 

 minute gradations, We have got far away from the old notion 



