Descendenz u. Hybriden. — Morphologie etc. — Physiologie. 5 



These results, while in accordance with Galton's original 

 views, do not accord so closely with more recent Statistical 

 observations. The value of parental correlation is not constant, 

 but varies about the values of 0,45 and 0,5 fraternal corre- 

 lation about 0,5 and 0,6, while the ratio of diminution is more 

 nearly 2 /s than 1 j->. The author considers this to show that this 

 Mendelian generalization fails when tested by actual numbers. 



Regression holds for the great bulk of a Mendelian popu- 

 lation, but grows gradually less as we treat the mating of nearly 

 pure allogenic parents, ceasing entirely with pure allogenic forms. 

 When the number of generations is indefinitely increased, the 

 probability of mating between pure allogenic individuals becomes 

 sensibly zero, and the regression on the mid-parent is absolu- 

 tely that given by Galton's theory. 



In a parental correlation table drawn up for a Mendelian 

 population the mean variability of the arrays of offspring is 

 o]/(i— r-), where o is the variabitily of the general population, 

 and r the coefficient of parental correlation. This mean value 

 exactly agrees with that given by Statistical results, but a pro- 

 gressive change of variability of the arrays in passing across 

 the table, such as is demanded by this Mendelian theory, has 

 not hitherto been observed. 



In conclusion, the author points out that a generalized 

 theory of the pure gamete is not ä priori inconsistent with 

 the broad conceptions of linear regression, parental correlation, 

 ancestral influence, and the distribution of frequency actually 

 observed in populations — and indeed the theory under dis- 

 cussion leads to these results. On the other hand there are 

 marked divergences between the results observed and those 

 deduced from a generalized theory of the pure gamete which 

 in the opinion of the author definitely prevent its acceptance 

 as a general theory of heredity. E. Drabble (London). 



Morgan, T. H., Polarity and Regeneration in Plant s. 



(Bull. Torrey Bot. Club. Vol. XXXI. April 1904. p. 227 



-230. 1 fig. in text.) 



Concludes that polarity in the plant does not govern bud 

 development in certain forms experimented with, but that it is 

 the relative state of development of the buds, existing in the 

 plant before the mutilation was performed. Polarity, therefore, 

 is not the cause of the flow of substances in the plant, nor 

 does it appear to be regulative in the matter of bud develop- 

 ment. H. M. Richards (New York). 



ASO, K., CanPotassium Bromid exert any Stirn ulating 

 Action on Plants? (Bul. College of Agriculture Tokyo. 

 Vol. VI. No. 2. 1904.) 



Bei Topfversuchen mit Bohne und Reis ergab sich, dass 



Bromkalium in Dosen von 10 mg. pro Kilo Boden den Ertrag 



