250 EXPEKIMENT STATION KECOfeB. 



The t-liuracters of the two parents were usually reproduced in the hybrids, though 

 oce-asionally new or atavistic tendencies were notable. Characters differentiating 

 the parent forms were usually blended together in the hybrids, or united unchanged 

 in mosaics of small or large iiattern. Of the blends, Blue Pod X Davis is cited. 

 The brown color of the seeds of Blue Pod united with the white color of the Davis 

 seed, to form light brown seeds. Golden Wax, a nearly stringless podded sort, united 

 with the Mohawk, a stringy podded variety, to produce a hybrid with pods less 

 stringy than Mohawk and more stringy than Golden Wax. The ratio of the length 

 to the thickness of seed of Stringless Green was found to be about 2.21, and of 

 AVarwick, 1.92. In the hybrid Stringless Green X Warwick, the ratio was 2.11. A 

 number of other examples of blends are cited. 



Mosaics were obtained when the white-seeded Davis was crossed with the red- 

 seeded Scarlet Flageolet, the hybrid seed being spotted red and white. A like mixture 

 of colors occ!urred in hybrids of Currie X (iolden Wax and Ward well X Challenge 

 Black, etc. Cases are also cited in which hybrid seeds took all their characters, such 

 as color, shape, size, etc., from one parent, while the characteristics of the pods, such 

 as color, shape, stringiness, etc., were taken from the other. Keeney X Davis is 

 cited as an example of this kind. This hybrid had white seeds like the Davis and 

 pods like the Keeney. Sometimes the characters of one parent were found mixed 

 with the blended characters of the tw^o parents. Thus some individuals of the third 

 generation hybrid Blue Pod X Davis had leaves and stems like the Davis, brown 

 seeds like Blue Pod, and flowers in which the dark bluish purple of the Blue Pod 

 was })lainly diluted by the white color of the Da\as. Instances are cited in wliich 

 hybrids could not be differentiated from one of the parents. Thus, "In second and 

 third generation hybrids of Blue Pod X Davis numerous individuals were so nearly 

 like Blue Pod that they could scarcely be distinguished from those races by any 

 characters of plant, pod, flower, or seed. The considerable number of reversions in 

 this case is s^pecially noteworthy because of the fact that the two parent races differ 

 in nearly all their characters." 



Those characters which were transmitted entire or almost unchanged in first gen- 

 eration forms, and termed "dominant" by Mendel (E. S. R., 1.3, p. 744), were found,, 

 as in Mendel's experiments witn i^eans, to be green-colored pods and a long plant 

 axis. Other characters which tended to impress themselves strongly in the first gen- 

 eration hybrids were dark seed colors and stringless pods. When green and yellow 

 podded races were crossed, the first generation hybrids had green pods, yellow and 

 intermediate colors not appearing until later generations. When semidwarfs and 

 dwarfs were (Tossed, the first generation hybrids were all semidwarfs, strictly dwarfs 

 not appearing until the second generation. Atavistic tendencies were found espe- 

 cially prominent in the pod colors whenever Davis or Mohawk was used as one of 

 the parents. This fact suggests that these races probably came originally either 

 directly or indirectly from such varieties as Horticultural, Goddard, etc. 



Investigation as to tlie cause of pithiness in celery, E. P. Sandsten and 

 T. II. White {Miiryland ,St(i. Bui. S3, 2jp. 110-119, fins. 5).— In 1900 two samples of 

 American and one of French celery seed were sown in similar seed beds and 200 

 plants from each seed bed selected for planting in an open field June 14. The plants; 

 in every case were given the same kind of cultivation and attention. When the cel- 

 ery was dug in Deceml^er it was fomid that 40 per cent of the plants grown from. 

 American seed were pithy, while not a single stalk of the plants from the French 

 seed was pithy. These results were so striking that the experiment was continued; 

 in 1901, seed being obtained from five different seed firms. The experiment that 

 year divided itself into two phases, early transi)lanted and late transplanted. One 

 hundred jilants were used in each instance. The results obtained during the season 

 are sliown in the following table: 



