750 JOURNAL OF THE ROYAL HORTICULTURAL SOCIETY. 



Assimilation of Nitrogen by the Root Nodules of Leguminous 

 Plants : Importance of the Removal of Products of Growth. 



By John Golding {Jour. Ayr. Sc. vol. i. part i., pp. 59-64 ; Jan. 1905). — A 

 preliminary note on experimental work which indicates that the removal 

 of the products of assimilation favours the continued production. — F. J. B. 



Aster, Contribution to the Life History of. By M. Opperman 



(But. Gaz. xxxvii. No. 5, p. 353). -This is a full description of the forma- 

 tion of the embryo-sac, nuclei, and antipodal cells. Of these it is 

 observed, " The fertilisation of an antipodal egg is clearly demonstrated in 

 Aster." — G. II. 



Atavism or Cryptohybridism. By Dr. Erich Tschermak (Wien) 

 (Beih. Bot. Cent. xvi. pp. 11-35). — Gives seventeen cases of the reappear- 

 ance of an ancestral character by crossing two varieties of which neither 

 possesses the character in question. The manner in which the characters 

 were observed to occur followed Mendel's law rather than that of Galton- 

 Pearson. The following were the cases examined : 



(a) Pisum arvense. — Red flowers appeared in hybrids of the pink 

 1 Svalofer ' races with white sativum races and with two 1 Victoria ' races 

 (neither red-flowered). Wrinkled seeds were fcund in hybrids of 

 ' Svalofer ' and 1 Victoria ' races, both of which have round seeds. Violet- 

 spotted seedcoats appeared in hybrids of the same two races (neither has 

 this character), but only when the pollen was from the ' Svalofer ' race. 

 Dark yellow-brown testa appeared in hybrids of the same two races. 

 Violet spots in the leaf axils also appeared in hybrids of the same two 

 races. 



(b) Phaseolns. — (1) Yellow and brownish-green to black marbled testas 

 appeared as the result of crosses of two races, neither of which had this 

 character. (2) The same with two other hybrids in five other experiments. 



(c) Matthiola. — Clear lilac flowers blooming late in the season appeared 

 as the result of crosses of dark red, early-flowering forms, and white- 

 flowered varieties. 



(d) Hordeum. — Six rowed barley as a cross between two-rowed and 

 four-rowed forms. Also a few four-rowed forms as a cross between a two- 

 ranked and a six-ranked variety. 



The discussion of these results leads to a confirmation of Mendel's 

 theory in many of the experiments, but the evidence of atavism in hybrids 

 is decidedly interesting. — G. F. S.-E. 



Atmosphere, moist and dry, Influence on Form and Structure 

 of Plants. By Ph. EWhardt (Aim. Sc. Nat., Bot. xviii. pp. 60 152 ; 

 1 plate and 17 figs. ; 1903). — After a summary of previous work, the 

 author proceeds to examine the growth of plants under moist and dry 

 conditions. The method followed is to grow seedlings or cuttings in an 

 apparatus which ensures a continuous exposure to either a moist or a dry 

 atmosphere, while check plants are grown under normal conditions. 

 The figures and description give an interesting comparison of the 

 growth under these conditions. Nineteen species are dealt with, includ- 

 ing Lupine, Scarlet Runner, Sensitive Plant, Broad Bean, Laburnum, 

 Poplar, Willow, ( otoneaster, Castor Oil, Aster, Fuchsia, Lilac, &c. The 



