Varietäten, Descendenz, Hybriden. 247 



the one of larger size than in the other. Classes of equal size in 

 frequency distributions of great variability appear to be arbitrary 

 and improper, if size factors are assumed to be dynamic factors 

 with fluctuations roughly expressed by the term growth force. To 

 Show thisaccelerative action, the class ranges must gradually increase 

 as the size (that is, the number of factors) increases. It is shown 

 that the distribution under discussion will be changed from skew 

 to normal if a simple arithmetical increase in the size of the classes 

 is made. Jongmans. 



Harris, J. A., Biometrie data on the in f lores cen ce and 

 fruit of Crinum longifolium. (Missouri bot. Garden. XXIII. Ann, 

 Rept. p. 75—99. 1912.) 

 The author gives the following summary and conclusions at the 



end of his paper. 



1. The primary purpose of this paper is the recording of quan- 

 titative data on the intiorescence, fruit and seed of Crinum longi- 

 folium for future use in comparative studies of fertility and fecundity 

 in plants. Such problems are immensely complex. Numerous forces 

 are puUing, sometimes in the same, sometimes in opposite directions. 

 Another investigator may find his material differing in some important 

 regards from that described here, because various conditions are 

 different. It is, therefore, only with the explicit Statement that final 

 conclusions must await the comparative treatment of wider series 

 of data, that the author indicates some of the points of more general 

 interest. 



2. On comparative grounds, one must assume that the anomalous 

 seed habit of C. longifolium j and other similar species, is not primi- 

 tive but probably recently acquired from an ancestral form producing 

 a large number of ovules per fruit, Several peculiarities of the 

 inflorescence and fruits may be referred to the large size of the 

 seed. The author notes that: 



a. Variation in the number of flowers produced or in the number 

 of fruits matured per inflorescence is not greater than that generally 

 found in inflorescences. The peculiarities of the seeds apparently 

 have not produced any effect on Variation in the inflorescence. 



b. The Variation in number of seeds per fruit, measured by 

 ränge, Standard deviation or coefficient of Variation is very great. 

 The distribution is also very skew. These conditions are probably 

 directly due to the existence of a large number of ovules in each 

 ovary (an ancestral characteristic?) of which only a partcan, because 

 of the great size of the seeds, be developed to maturity. 



c. The distribution of seed weight is very skew and the variability 

 very high. This is probably to be attributed to the limitation imposed 

 upon the tendency of a large number of ovules to develop into 

 seeds by the inadequacy of plastic materials for all. 



3. There is a moderately close positive correlation of the order 

 r = . 35, between the absolute members of flowers formed and 

 fruits developing per inflorescence. The correlation between the 

 number of flowers per inflorescence and the deviation of the number 

 of fruits developing from the probable, on the assumption of 

 proportionate fertility throughout, is negative in sign and of about 

 the same order of magnitude. The larger inflorescences are. 

 therefore, less capable of maturing their ovaries into fruits than 

 are the smaller ones. 



