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The Journal of Heredity 



between it and the color from which it 

 has proceeded" (p. 59); in other words, 

 as we should say today, dilution through 

 the presence of but a single dose of the 

 color factor. 



The most interesting portion of Ver- 

 lot's memoir is his discussion of the 

 practical results achieved with orna- 

 mental plants in the field of hybridiza- 

 tion. Regarding dwarfing he cites 

 McNab (p. 42), to the effect that the 

 best dwarf varieties of rhododendron 

 are obtained by the use of pollen taken 

 from the small stamens, "the products 

 of which," he says, "I am able to 

 certify, are very different from those 

 obtained by the use of the pollen of the 

 large stamens." Regarding breeding 

 for winter hardiness, he mentions the 

 case of the cross of Amaryllis brasiliensis, 

 a delicate species impossible to winter 

 out of doors, by Amaryllis vittata, a 

 much hardier plant, whereby hybrids 

 were produced which, with light cover- 

 ing, would support the climate of Paris. 

 Likewise Rhododendron arbor eum, which 

 cannot resist more than 2 to 3 degrees of 

 cold, gave, when crossed by R. cataw- 

 biense (a much hardier form, though with 

 inferior inflorescence) , hybrids which in- 

 herited the hardiness of the female plant. 



Verlot did not recognize the phe- 

 nomenon of dominance in the first 

 generation of the hybrids, but he men- 

 tions the case of a white Gloxinia crossed 

 by pollen from a blue-fiowered variety, 

 in which out of one thousand seedlings 

 "all bore nothing but perfectly blue 

 flowers, not a single one of them being 

 white, nor a single one variegated" 

 (p. 65). Likewise the crossing of the 

 same plant by a red-flowered variety 

 gave the same result, "all the plants 

 coming from sowings of seeds thus pro- 

 duced had entirely blue flowers" (p. 65). 



Regarding the inheritance of variega- 

 tions it may be of simple interest to note 

 that the following species are mentioned 

 in which the variegated form breeds 

 true from the seed. Alyssum mariti- 

 mum, Barbarea vulgaris, Celtis australis, 

 Cheiranthus cheiri. With these are to 

 be included the variegated ferns Pteris 

 argyraea and P. aspericaulis var. tricolor. 



He remarks upon an interesting fact 



that the variegations do not appear 

 upon the first leaves of a variegated 

 variety. Regarding the heredity of 

 double flowers, he reports no crosses, 

 but simply remarks upon cases of 

 double-flowered peach and apple which 

 came true from the seed (p. 83). 



Another interesting piece of informa- 

 tion given is that, in the case of double 

 camellias, the full round seeds pro- 

 duced plants with very double flowers, 

 while the more elongated seeds pro- 

 duced plants with single or but slightly 

 doubled flowers (p. 87). Among color 

 variations in plants, few are more 

 interesting than the red or copper- 

 leaved forms of ordinary green-leaved 

 types. It may be of interest here to 

 note Verlot's citations of such color 

 varieties as are homozygous for the 

 color, and which hence come true to 

 type, among the recorded instances 

 being the purple beech and the purple- 

 leaved barberry. 



One of the most interesting matters 

 recorded in Verlot's paper, is his cita- 

 tion of Bridgmann's investigations 

 on the inheritance of leaf variation in 

 ferns. Many species of ferns show 

 various degrees of leaf laciniation, the 

 latter becoming often many times com- 

 pounded. In the case of several species 

 of Scolopendrium with crisped or lacini- 

 ate leaves, spores were separately sown 

 from the modified and from the un- 

 modified leaves, with the result that 

 the resulting plants, although derived 

 from the same original plant as a parent, 

 inherited the characteristics of the 

 particular leaves or parts of leaves from 

 which the spores were taken. 



"The spores from the deformed part 

 of the frond were collected and sown 

 separately. . . . The result was 

 that all the plants which came from 

 them reproduced the crisped form of the 

 individual mother plant, and some of 

 them even in a higher degree" (p. 98). 



"The spores from the normal part 

 of the frond, which had furnished the 

 first sowing, were collected with the 

 same care, and sown under identical 

 conditions. There originated in the 

 same way thousands of young plants, 

 but it was scarcely possible in the 



