126 CARNEGIE INSTITUTION OF WASHINGTON. 



by pollination with normal plants throw offspring with about 79 per 

 cent showing the pecuUarity in the seedUng stage. The proportion of 

 abnormal plants depends roughly upon the strength of the abnormality 

 in the capsule producing the seed. In a single instance good pollen 

 was obtained from an abnormal plant and crosses showed that the 

 abnormahty is transmitted through this pollen. Normal plants 

 grafted on abnormal plants take on the complete abnormal complex, 

 as shown in the new leaves, flowers, and fruits which subsequently 

 develop. The abnormality, therefore, looks Uke a bacterial disease. 

 Inoculations, however, with expressed juice of the abnormal plants 

 have so far failed to infect normals. 



One of the mutations in the jimson weeds is of considerable interest, 

 since it suggests the way in which a new species having once originated 

 by mutation may be able to estabhsh itself as a perfectly distinct form 

 without intergrading with the parent species alongside which it is 

 growing. The mutation in question is perfectly self-fertile and the 

 sibs in its offspring are fertile inter se and with the original parent 

 mutant. Neither the mutant nor its offspring (with doubtful excep- 

 tions) have been found capable of crossing with any of the several 

 different lines that we have under cultivation. 



In Portulaca, a dwarf mutant has been found which apparently acts 

 as a Mendehan recessive, but which occasionally produces branches 

 reverting to the normal type which are heterozygous for the dwarf 

 character. Other vegetative segregations as well as doubling and 

 color types of flowers in this species are being studied. Doubling in 

 Portulaca seems to be a Mendehan dominant, the homozygous full 

 doubles having the stamens and pistils so strongly transformed into 

 petals that they rarely set seed, the heterozygous semi-doubles segre- 

 gating according to expectation into full doubles, semi-doubles, and 

 singles. 



Doubling and self-fertility are under investigation in Helianthus. 



Verbena is being investigated for color-characters and self-fertihty. 

 The pollen of individual plants may be largely imperfect. The number 

 of seeds produced by bagged clusters seems roughly proportionate to 

 the amount of good pollen produced by the flowers. 



For a number of years Dr. Blakeslee has been growing pm-e lines of 

 the adzuki bean (Phaseolus angularis) largely for class demonstration 

 purposes. The species is largely grown in Japan for human food and is 

 reported to be, next to the soy bean, the most prolific yielder of seed of 

 the leguminous plants in cultivation. In the vicinity of Washington, 

 D. C, it gives about twice the yield of the common navy bean. Unlike 

 the soy bean, which has to be prepared commercially, the adzuki bean 

 m^y be used in the home in the same way as is the navy bean. Its high 

 yield and its freedom from the so-called rust which has ruined the bean 

 industry in certain regions suggested the adzuki as a valuable plant to 



