836 



If Bauer's "Einführung in die experimentelle Vererbungslehre" 

 had jit that time already appeared, I should probably have chosen 

 two other forms, differing in more characters, in order to be able 

 to investigate whether there exists a connection between reduction- 

 division and Mendelian segregation, as Bauer considers possible. 

 Since there ai-e only 3 chromosomes in the reproductive-cells of 

 Canna indica, only three characters can independently segregate 

 according to Mendel if the hybrid-segregation is based on the division 

 of the chromosomes of the parents. 



The chance that two varieties, which only differ outwardly by 

 the possession and absence of a red colour in almost all their aerial 

 organs, might differ in more than three characters, is at first sight 

 small. Yet this must be the case here, because from the proportions 

 in which the self-pollinated ''red" plants segregate as well as from 

 those of the second generation of hybrids it is seen that even for 

 the red edge of the leaves alone the cooperation of three factors is 

 necessary, whilst the colour of the fruits requires at least one additional 

 factor. For this reason the hybridisations have from a theoretical 

 standpoint become of greater importance than I at first suspected. 



The Canna indica without the red colouring matter has remained 

 constant to the fourth generation. I have had in all 165 specimens, 

 descendants of 14 mother-plants. All are descended from a single 

 "green" GVi. 



The "red" Canna on sowing was seen to be a hybrid. Only 

 from two specimens, R 4 and R 13 did I obtain seeds by self- 

 pollination, from most of the others only a little seed after free- 

 pollination. This fact makes it probable that these plants were 

 homozygotically "red", because later I very often got few seeds or 

 none from the pure "red" individuals and a sufficient number from 

 the hybrids. Seeds were obtained after self-pollination from 20 des- 

 cendants of R 4 and from 25 of R 13 and although in many 

 cases the proportions, by reason of the small number of specimens, 

 were not wholly certain, yet it was established that segregation 

 occurs in three different ways: 



a. In the proportion 3 : 1 (e.g. 27 red and 10 green ; 44 red and 

 15 green; 69 red and 19 green; 24 red and 8 green). 



/>. In the proportion 9:7 (e.g. 146 red and 123 green [theoreti- 

 cally 151.3 red and 117.7 green]; 53 red and 38 green [theoreti- 

 cally 51.2 red and 39.8 green]; 31 red and 24 green [theor. 30.9 

 and 24.1]; 41 red and 29 green [theor. 39.4 and 30.6J). 



c. As 27:37 (7 red and 10 green | theor. 7.2 and 9.8j ; 11 red 

 and 15 green [theor. 11.0 and 15.0]. 



