311 



28. The enormous polymorphy characleri/.ing Ihe seclion Caninae 

 niight, to a large exlenl. be ascribed lo Ihis obvious hybridism. 

 However, mulalion phenomena have no doul)l conlrii)uled lo Ihe 

 polymorphy. In Ihis case, Ihe mutations must be vegetative, pro- 

 duced in apomictical stocks. Matsson (Svensk Bot. Tidskr. 1912) 

 has in a sowing of tomentosa *subcristala found some forms dilTe- 

 ring from the mother. Tlie llowers had not been castrated. 

 Neverlheless, that one of these new forms Avhich I examined pro- 

 bably was not produced in a sexual way, is evident from Ihe 

 chromosome set being (juite the same as that of Ihe invcstigaled 

 /om<v?/o.sa forms representing Ihe Fj-type (7 gemini and 21 unpaired 

 chromosomes). 



Botanical Labralory, Stockholms Högskola. June, 1920. 



