270 



The Journal of Heredity 



THE ORIGINAL DWARF PLANT 



Figure 12. The dwarf measures about 50 

 cm, from crown to tip of awns; the parent 

 measures about 95 cm. There are seventeen 

 cuhns divided into twentv-eitjht branches 

 (See text, p. 269.) 



a height of 125 centimeters and pos- 

 sessed over 50 nodes. The greater 

 lengths came from the development of 

 vegetative branches on the inflores- 

 cence. These inflorescences often pro- 

 duced no fertile flowers, while fre- 

 quently one or more vegetative branches 

 at the lower nodes of the modified 

 rachis developed into a culm similar to 

 the original one. There is a gradual 

 transformation of culm to rachis and 

 of vegetative leaves to floral leaves, 

 which it is the intention of the writers 

 to discuss in a later paper. 



One of the longer culms is un- 

 branched for 82 centimeters and has 

 internodal lengths ranging from 5 to 7 

 centimeters near the crown to 1.5 to 

 2.5 centimeters near the first inflores- 

 cence. One of the vegetative branches 

 of this inflorescence is 35 centimeters 

 long and has 29 nodes to the base of 

 the second inflorescence. Many of 

 these \egetative branches remained 

 green and actively growing after the 

 culm below had turned brown. Many 

 attempts at crossing these greenhouse 

 plants were made, but due to the ab- 

 sence of the near-normal spikes on 

 greenhouse plants, little success at- 

 tended these efforts. 



Figure 13 shows a second portion 

 of the plant with the leaves removed to 

 show the branching which sometimes 

 occurs at an inflorescence. Prolifera- 

 tions are to be seen on two of the 

 branches. Figure 14 shows one of the 

 modified spikes from a greenhouse 

 plant. 



Two seeds were sown in the nursery 

 at Aberdeen, Idaho, in 1919. Both 

 germinated and produced many-noded 

 plants which again were only about 

 50 cms. tall. These plants produced 

 many abnormal spikes containing a 

 few seeds and two or three rather small 

 spikes of nearly normal appearance. 

 The culms which bore the more nearly 

 normal spikes had fewer nodes and a 

 much more nearly normal appearance 

 than the others. 



At Aberdeen, in 1920, plants of this 

 dwarf form were grown which pro- 

 duced several nearly normal heads, and 

 hybrids with several different varieties 

 of barley were made successfully. In 



