GENETICS IN SWEDEN 103 



mental plant. He has been able to show, thanks to the discovery of a new color 

 variety (light purple), that the ordinary flower color in Pisum arvense, held to 

 be a simple character and an allelomorph to white by Mendel, depends on three 

 complementary factors. Tedin may serve as a type of the strict analyst, who 

 works with extensive progenies and numerous controls, tying the chain of proof 

 methodically and definitively. 



The versatile mind of Birger Kajanus, another Swedish geneticist, contrasts 

 greatly with the persistent disposition characteristic of Tedin. His temperament 

 marks both his material and his theoretical point of views. He has published a 

 great number of papers dealing with widely different genera and characters. He 

 has collected his thoughts on greater problems in two cases, viz. with regard to 

 the inheritance of the color and the shape in roots (Beta and Brassica), and with 

 regard to the flower color and other characters in Papaver Somniferum. His 

 theoretical point of views, as seen in his publications dealing with Beta and 

 Brassica, pass from enthusiastic Mendelism to Lamarckism and scepticism, and 

 back to practical Mendelism. His work on Papaver is a pure analytical work. 

 His extensive and long continued experiments with crosses between different wheat 

 species seem to be of great interest both analytically and phylogenetically, to judge 

 from preliminary notes already published. 



Hans Rasmuson has combined analytical investigations with the species problem. 

 He was engaged as vine breeder in Germany for some years and worked expecially 

 with the problem to raise vines which combined the fine quality of the European 

 varieties with the resistance of the American varieties towards the vine^disease 

 (Phylloxera). The war put a check to these investigations, but it was found that 

 immunity is dominant, and that in some cases monohybrid segregation, in other 

 cases more complicated segregation, takes place. The characters of different species 

 as well as of different varieties of Vitis seemed to segregate in Mendelian ratios. 

 The same has been found by Rasmuson to take place in the genus Godetia, where 

 the both species Whitneyi and amoena have been found to segregate with regard 

 to morphological characters. A close analysis of the flower colors of these species 

 has also been made. These investigations give the interesting result that the genus 

 Godetia, although belonging to the same family as Oenothera, does not show 

 any of the complications of segregation characteristic of the latter genus. 



In addition several smaller papers and analyses have been published by 

 Rasmuson dealing with Impatiens Balsamina, Petunia, Papaver, Tropaeolum, Malope, 

 Clarkia and Collinsia. 



Carl Hallq^vist has published an investigation of the flower color and seed color 

 in Lupinus angustifolius, which with regard to both analytical distinctness and extent 

 forms a beautiful analogue to the pea investigation by Tedin, mentioned above. It 

 is also valuable from a purely analyticaUmethodical point of view; he describes a 

 method to determine the degree of coupling through determining the ratio in F3 

 between progenies of different segregation types, which makes the result more reliable 

 than a determination based on the segregation ratios found in the F2«generation. 



HALLQ.UIST has also contributed to the question of polymery, viz. in a paper 

 dealing with the inheritance of the flesh color and the shape of the leaves in 

 the Swedish turnip (Brassica napus). 



