Vererbung, Variation, Mutation. 163 



Arizona persistent selection for niany years of the best cotton plants caused some 

 improvement in earliness and pi*oductiveness and in the quality of the fiber. An 

 example of this phenomenon in Egyptian cotton is afforded by the Nubari and 

 the Yuma varieties. Ever since mutation became recognized as a factor in the 

 breeding of Egyptian cotton the following methods have been followed in Arizona: 

 1. Recognition and isolation of desirable mutants; 2. selection and comparison on 

 the progeny-row basis of those individuals among their progeny which express 

 most f ully the desirable characters of the ne w type ; 3. elimination f rom the seed 

 increase fields, preferably before blossoming begins, of the aberrant and otherwise 

 undesirable individuals. Three varieties, the Yuma, Gila and Prima have been ob- 

 tained which by the individuality of the parent plant together with the uniformity 

 shown by their progeny during subsequent generations indicate that they are of 

 mutational origin. Pearl. 



395) Babcoek, E. B., Studies in Juglans. IL Further Observations on 

 a New Variety of Juglans Californica Watson and on Certain Sup- 

 posed Walnut-Oak Hybrids. In: Univ. Cal. Pub. in Agr. Sei., Vol. 2, No. 2, 

 S. 47—70, Oct. 1914. 



In this paper the author reports the results of his work in determining 

 the nature and origin of a new variety of California Black Walnut, Juglans Cali- 

 fornica var. guercina. Its origin through hybridization with the Coast Live Oak, 

 Quercits agrifolia Nee is first considered. Attempts were made to hybridize the 

 two species but in neither the F x trees or F 2 seedlings was there any indication 

 of oak characters. The ¥ l trees obtained may possibly have been the result of 

 abnormal embryogeny due perhaps to Stimulation by the oak pollen but without 

 the oecurrence of fertilization. A further indication that the new variety is not 

 a cross between the two species is that it is produced from a Single tree in a 

 row of 21 California Black Walnuts year after year and that no oaks are in its 

 vicinity. Testing the origin of the new form from abnormal flowers or nuts the 

 author comes to the conclusion that the mere fact of teratology will not suffice 

 as an explanation. Finally the origin by mutation in apparently normal flowers 

 and fruits of Juglans californica is considered and here the evidence is definite 

 and sufficient. Of a total number of seedlings grown from nuts from the tree 

 producing the new variety, 5 per cent. were quercina. There is a possible rela- 

 tion between location in the Cluster and produetion of quercina seedlings since 

 only one nut in a Cluster produces the quercina form. Cytological investigations 

 are under way to determine whether abnormal mitosis or parthenogenesis is the 

 cause of the supposed hybrid. There is a discussion concerning whether hybri- 

 dization is necessary for the oecurrence of mutation. Pearl. 



39G) Haynes, W., Inbreeding in Dogs. In: Jour. of Heredity, Vol. V, No. 8, 

 S. 368—369, Aug. 1914. 



This paper reports the results of an analysis of records on two breeds of 

 dogs, the Airedale and Scottish terriers, to discover what proportion of registered 

 dogs are inbred. The conclusion is reached that neither inbreeding nor close line. 

 breeding is used as much by dog breeders as is generally supposed, and that of 

 the two Systems, linebreeding has been the more produetive of results. 



PearL 

 397) Belliiig, J., Inheritance in Plant Hairs. In: Jour. of Heredity, Vol.V. 

 No. 8, S. 348-360, Aug. 1914. 



The results set forth in this paper are upon the crossing of Florida Velvet 

 bean and another species of Stizolobium, the Lyon bean. The following working 



11* 



