EXPERIMENTAL EMBRYOLOGY 



387 



ficial cultures of the embryos and succeeded in obtaining mature 

 plants from them. The procedure adopted was to split the stony 

 endocarp with a scalpel, cut carefully through the integuments, 

 nucellus, and endosperm, and drop the embryos under aseptic con- 

 ditions into bottles containing nutrient agar. The seedlings aris- 

 ing from them were first transplanted to sterile sand watered with 

 a nutrient solution, then to soil, and finally grown in the field. 



Fig. 209. Inflorescences of Hordeum jubatum (A), Secale cereale (C), and hybrid 

 between them (B) raised by artificial culture of excised embryo. (After Brink, 

 Cooper, and Ausherman, 1944.) 



In time they developed into vigorous fruiting trees. A similar 

 technique used for the embryos of 7m is illustrated in Figs. 204-208. 

 It has been observed that in crossing Hordeum jubatum and Secale 

 cereale fertilization takes place within 4 hours after pollination but 

 the hybrid seeds collapse and fail to germinate. Brink, Cooper, 

 and Ausherman (1944) dissected out the hybrid embryos from 

 9- to 12-day-old seeds and reared them in artificial culture. The 

 embryos attained considerable growth and one of the seedlings grew 

 into a mature flowering specimen (Fig. 209). No seeds were set 

 on this plant, but the fact that the hybrid was able to attain the 



