Gates, Tetraploid Mutants and Chromosome Mechanisms. 



The next race to be mentioned I shall refer to as 0. g/'gas, 

 Sweden. It originated from a single mutant which appeared in 

 1907 in a pedigree culture of about thirty 0. Lamarckiaiia plants 

 which were grown by H. Heribert Nilsson (19U9) at Lund. My 

 seeds of this race were kindly sent to me by Nilsson, for corn- 



Fig. 3. 0. gigas Sweden. Rosette July 10. Cult. - 



SHI 



II. 3. 



parison with the other races of 0. gigas. They correspond to the 

 "Komb. 7" of his paper. Though clearly a giant form, the follow- 

 ing description will show that it is a characteristic race, differing 

 constantly from the gigas from Amsterdam and the one from 

 Palermo 20 ). From Nilsso n's pedigree seeds I grew thirty-six plants 

 as culture 233 / 12 . They were a uniform progeny except for certain 



20) Since this was written, an important paper by Nilsson (1912) has appeared, 

 with descriptions of this and other forms based upon extensive cultures. Such 

 studies as these are particularly valuable in making possible a correlation of the 

 results obtained by various investigators. The facts stated in my paper with regard 

 to 0. gigas Sweden are to be regarded as merely confirmatory of the previous 

 studies of Nilsson with that interesting mutant. The value of Nils son's experi- 

 ments in greatly enhanced by the fact that his cultures were derived from an 

 independant, aud slightly different, race of 0. Lamarckiaiia from a garden in 

 Southern Sweden. 



