HYBRIDISATION AND WHEAT HYBRIDS 379 



1. Typical dicoccoides. 



2. A dicoccoides-\ike form with short awns. 



3. A beardless form resembling T. Spelta. 



4. A long-eared T. vulgar e. 



5. A form with characters of T. dicoccum with short awns. 



6. A dense-eared durum-like form. 



The F 3 progeny of these were : 

 From plant i, only typical dicoccoides. 

 ,, ,, 2. (a) dicoccoides (red-chaffed). 



(b) semi-bearded forms approximating to cultivated T. dicoccum 



with non-hirsute rachis, some with red chaff, others with 

 white chaff. 



(c) sterile, beardless T. vulgar e, dark brown chaff. 

 ,, ,, 3. (a) beardless Spelta-like forms, white-chaffed. 



(b) sterile, beardless, red-chaffed vulgare. 



(c) fertile, beardless, white-chaffed vulgare. 



(d) fertile, beardless, red-chaffed vulgare. 



,, 4. (a) beardless, lax-eared, red-chaffed vulgare. 



(b) beardless, dense-eared, white-chaffed vulgare. 

 ,, 5. (a) T. dicoccoides (red-chaffed). 



(b) beardless, dicoccum-like forms, white- and red-chaffed, 



with smooth or hirsute rachis. 



(c) beardless, red-chaffed and white-chaffed sterile vulgare. 



(d) beardless, dense-eared, sterile, durum-\ike forms, some of 



them " freaks." 

 ,, ,, 6. (a) black-chaffed and red-chaffed dicoccoides. 



(b) a long-awned sterile durum. 



(c) beardless dicoccum-like forms, some with hirsute, others 



with glabrous rachis. 



(d) several beardless, dense-eared durum and vulgare " freaks." 



Most of them sterile. 



In morphological characters the glumes are very variable, and among 

 the segregates resembling the cultivated wheats there is an almost con- 

 tinuous series of intermediates between completely sterile forms and those 

 with all the spikelets fertile. While the majority possess easily disar- 

 ticulated ears, there are many with various degrees of brittleness of the 

 rachis and similar diversity in the habit of growth and time of ripening of 

 the several forms. 



In general characters these segregates resemble those obtained by 

 Tschermak, who states that the F 2 generation of a hybrid between T. 

 dicoccoides and T. vulgare gave a mixture of T. Spelta, T. dicoccum , T. 

 vulgare, and T. durum. 



Some of the progeny including the dense-eared " freaks " are singu- 



