1919] HOKTICULTURE. 739 



inheritance tlie autlior presents some notes on tlie technique of crossing, based 

 on his own experiences. 



Thus far the author has failed to find a case of a female flowering plant 

 becoming male or hermaphrodite; wliereas it is almost impossible to say that 

 a given apparently male plant will not set an occasional well-developed fruit 

 or an occasional seed. The crossing of species has not resulted in any fruit 

 markedly larger than either of its original parents. No free fruiting plants 

 have been obtained from crosses made with vesca X daltoniana, garden varieties, 

 and chiloensis. The author is inclined to believe that vesca has nothing to do 

 with the present garden varieties. 



Berry fruits and berry wines, M. Lebl {Beerenobst und Bcerentcein. Berlin: 

 Paul Parey, 1915, 3. rev. ed., pp. VI -{-114, fid^- 39). — A treatise, revised by G. A. 

 Langer, on the culture of bush and cane fruits, strawberries, and rhubarb, in- 

 cluding directions for making wine and fruit juices. 



The limits in hybridization of Vitis rotundifolia with related species and 

 genera. — First report, L. II. Detjen {North Carolina Sta. Tech. Bui. 17 {1919), 

 pp. 5-26, figs. S), — A brief review of the work of earlier grape breeders, with 

 special reference to the hybridization of V. rotundifolia, and an account of 

 work done along this line at the station from 1912-1918, inclusive. A list of 

 cited literature is gven. 



The work thus far conducted at the station shows that V. rotundifoUa will 

 hybridize with V. munsoniana and some species of Euvitis, namely V. vinifera, 

 V. hourquiniana, V. labrusca, V. cordifolia, and V. cestivalis, also with the 

 varieties Winchell, Concord, and others. The limits of hybridization have not 

 been established, but the results indicate what may be expected in hybridiz- 

 ing rottmdifolia with the above related species and genera. 



Rotundifolia will also hybridize with its own Fi hybrids with other species of 

 Vitis. When used as the male parent it will hybridize quite readily with some 

 species of Euvitis, but when used as the female parent it will hybridize only 

 rarely. Certain combinations are more congenial for hybridization than others. 

 Rotundifolia failed to hybridize either way with such related genera as Par- 

 thenocissiis quinquefoJia, P. tricuspidata^ or Ampclopsis heretopliylla var. 

 elegans. 



Other species are to be reported on later as time and material permits, but 

 the author considers that it is doubtful whether rotundAfolia will hybridize 

 with all species of Vitis. 



Some Fi hybrids of Vitis rotundifolia with related species and genera, 

 L. R. Detjen {North Carolina Sta. Tech. Bui. 18 {1919), pp. 51, figs. 33).— Dur- 

 ing the course of the above-noted study numerous hybrid plants of different 

 parentage have been produced. This bulletin gives a list of nine parental 

 combinations effected and describes and illustrates the characters of several 

 hybrid vines. A general survey is then given of the hybrid characters in Fi, 

 and the status of so-called " false hybrids " is discussed. 



A careful study of hybrids derived from V. rotundifolia and such other species 

 as V. vinifera, V. labrusca, V. bourquiniana, V, cordifolia, and the hybrid variety 

 Winchell indicates that they are generally more or less intermediate in char- 

 acter. The Rotundifolia group when hybridized with Eiivitis species Is less 

 prepotent as to external characters than has generally been supposed. Such 

 hybrids are almost sterile, and this sterility is due mainly to hybridization, 

 especially in perfect hermaiihrodite forms. In the imperfect hermaphoditic and 

 staminate vines, sterility is due to the double phenomenon of sex or intersexual- 

 Ism and hybridization. 

 153351°— 20 1 



