194 University of California Publications in Agricultural Sciences [Vol. 2 



plant but failed to appear on the other. After remaining alive, but 

 not growing, for eighty-one days the plant with the rudimentary 

 plumule died. The one failing to produce even the rudimentary 

 plumule leaves lived for a shorter period. 



After this unsuccessful attempt, tvvelve remaining achenes were 

 placed in the germinator. At the end of five days five had sprouted, 

 four of which show-ed robust, healthy cotyledons which resembled those 

 of tectorum seedlings but on an enlarged scale. They were essentially 

 as the first two plants secured from the same lot of seed. After having 

 produced abnormally large cotyledon leaves, and in some cases rudi- 

 ments of plumule leaves, all the seedlings began to turn yellowish, and, 

 despite efforts to revive or stimulate them, continued to decline until 

 finally they died. 



One of the plants which was beginning to show signs of distress 

 was carefully removed from the soil by w^ashing in a pan of water. 

 The root was one inch long and had a blunt rounded tip covered by 

 the rootcap. All along the root from the tip to the ground surface 

 line were small knots or wartlike protuberances as if lateral roots 

 might have been attempting to push out. Later' cytological examina- 

 tion showed this to be the case. The root and the cap were turning 

 brownish as if growth had cea.sed and decomposition had l)egun, 

 although the above-ground parts had only begun to show signs of 

 unhealthiness. The fifth plant of this culture was smaller than the 

 others but otherwise like them. 



When the plants began to show symptoms of declining health some 

 of them were treated with ether in an effort to stimulate them to new 

 growth, but this appeared to have no effect and all perished. 



Z 7 Fi (18.204 P, X p2 P^i) capillaris X tectorum 



Eight Fj achenes were produced. Three out of five achenes pro- 

 duced seedlings wliidi showed their hybrid nature by developing large 

 tectorum-\We cotyledons, by their failure to produce plumule leaves, 

 and by their inability to pass beyond the cotyledon stage. 



Z8 Fi (18.201 Pi X p2 Pr.i) CAPILLARIS X TECTORUM 



Only one achene was produced on one iiead washed free of its own 

 pollen and i)ollinated with tectorum pollen. This achene produced a 

 seedling which appeared to be intermediate between its parents, and 

 like other hybrid seedlings died at the end of the cotyledon stage. 



