1010] FORESTRY. 541 



typos of chrysanthemums and their special cultural requirements* manures and 

 fertilizers, the exhibition of blooms and plants, ami pests and diseases. The 

 work concludes with several selections of varieties tor various purposes. 



Studies of inheritance in the Japanese Convolvulus, B, M'yazwva (four. 

 Genetics, 8 < mi8), No. l, pp. 59-82. pi. l, fig. O— Reciprocal crosses were made 

 between yellow-leaved white-flowered plants and green-leaved dark-red-flowered 

 plants of the Japanese morning-glory. Data are given for four generations on 

 the transmission of leaf and flower colors. 



The green color of leaves was dominant to yellow with a ratio of .^:1 in Fj. 

 A factor producing "hukurin" (marginal white) was present In the white- 

 flowered parent, it was dominant to full color, segregating 3: l In Fi. 



With the factor for green leaf-color denoted by and that for dark-red 

 flowers by /'. and with one parent denoted by t;<;hl> and the ether by ggdd, 

 there is an Interrelation between the factors G and D. In the presence of D 

 the production of the dark-red color takes place when C is present in homozy- 

 gous condition, and that of red (magenta or scarlet) color when <; is present in 

 heterozygous condition or altogether absent. The Fi crosses (GgDd) will 

 always bear flowers of magenta red. 



Dahlias and their culture, M. A. Howe {Jour. Hort. Sor. N. V.. 2 (1919), No. 

 20. pp. 285-S01, pi. 1, figs. S). — In this paper the author briefly discusses the 

 origin, relationships, and classes of dahlias, gives specific cultural directions, 

 and presents a list of some sixty varieties recommended for garden decoration 

 and general effective results. 



New species of Rhododendron, B. Balfour (Notes Roy. Bot. Qard. Edinb., 

 10 (1917), No. 47-48, pp. 79-166). — Forty new species of Rhododendron are here 

 dev, Tilled. 



Note on the origin of a mutation in the sweet pea. R. 0. Punnett (Four. 

 Genetics, 8 (1918), No. I. pp. 27-31, fig. 1).— The mutation here discussed h? a 

 "cretin" or monstrous form, of which the chief characteristic is the straight 

 stigma protruding through the cleft keel. The standard and wings are gener- 

 ally smaller than in the normal flower and fail to expand fully. The 

 author presents the data secured in connection with the appearance of this 

 form of sweet pea in some pedigree cultures, and arrives at the conclusion 

 that the cretin always behaves as a simple recessive, and that the original 

 plant arose, not through the union of two germ cells which had lost the normal 

 factor, but through some radical alteration in the zygote after union between 

 two normal gametes had already taken place. 



FORESTRY. 



Regional spread of moisture in the wood of trees. — I, Deciduous-leaved 

 trees during the period late autumn to early spring, W. (J. Ckaib (Notes Roy. 

 Bot. Gan!. Edinb., 11 (1918), No. 51, pp. IS, pis. 10).— The study here reported 

 was conducted with Acer pscudoplatanus trees grown under similar conditions 

 in the Royal Botanic Garden. Determinations were made of the moisture con- 

 tent of different parts of the trunk of felled trees in October, December, Janu- 

 ary, and .March. The results are presented in a series of graphs and colored 

 illustrations and further discussed. 



Summing up the evidence secured, it appears that with the cessation of foliar 

 activity for the season the tree immediately commences its preparations for 

 the next season. As a result of the water moving inward from the outer zones, 

 beginning at the base of the trunk there is created an area of maximum moisture 

 content in a transverse plane at the center of the trunk. This inward current 

 and the consequent plane of maximum moisture content at the center gradually 



