480 ° BOTANICAL GAZETTE [JUNE 
brum and Paspalum dilatatum. In the former light is not necessary for ger- 
mination; but it shortens the required ‘“after-ripening” period and increases 
somewhat the percentage of germination. For complete ‘‘after-ripening’’ 
30 or more weeks of dry storage are required. A period in a seed bed at low 
temperature does not favor germination. In P. dilatatwm 1 or 2 weeks at 
o-60° C. dry storage brings about after-ripening. A period in the seed bed 
at low temperature is effective if it follows 20-30 weeks of dry storage. In 
this species light does not favor germination. This paper, as did the earlier 
one,* shows lack of exact analytical methods.—WILLIAM CROCKER. 
Embryo sac and embryo of Clematis Sources” has undertaken the 
investigation of the embryo and embryo sac of the Ranunculaceae, the four 
parts cited dealing with the Clematideae. The general situations in the 
family are well known, so that the usefulness of the present account consists 
in the elaboration of the details of a single tribe, presumably to be followed by 
similar accounts of other tribes. Perhaps there is some over emphasis of a 
definite sequence of stages in embryo-formation, for cell-successions have 
proved to be quite variable, and such uniformity as can be observed is prob- 
ably an indication of the uniformity of conditions in which the successive 
divisions occur. There is certainly evidence of a lack of familiarity with the 
literature of the subject.—J. M. C. 
The embryo of the Bromeliaceae.—GaTIN® has investigated the structure 
of the mature embryo and the germination of representatives of the Brome- 
liaceae. The three tribes were represented by a species from each of the 
following genera: Karatas, Billbergia, Aechmea, Puya, and Tillandsia. The 
variations uncovered are so considerable, and so doubtful as to their signifi- 
cance, that no general conclusion can be reached. The paper, therefore, is a 
contribution of facts that may become of service.—J. M. C. 
Light a form-stimulus.—DuBArp and BucuET* believe that light intensity 
determines the nature of the relief configuration of the hymenial surface of 
Merulius lacrymans. In high light intensity the surface shows high irregularly 
anastomosing ridges and deep depressions. In low intensity the furrows and 
ridges are less marked, and are arranged parallel to the incident rays of light. 
—WILLIAM CROCKER. 
8 Bot. GAZETTE §1:76-77. 1911. 
*9 SouEcEs, E., Recherches sur l’embryogénie des Renonculacées. Bull. Soc. 
Bot. France IV. 10: 242-250, 266-275, 509-517, 560-576. figs. 56. 1910. 
%°Gatin, C.-L., Premiéres observations sur l’embryon et la germination des 
Broméliacées. Rev. Gén. Botanique 23: 49-66. figs. 32. I91I. 
UBARD, M. M., et Bucuet, S., De l’'action de la lumiére sur le Merulius 
lacrymans. Bull. Soc. Bot. France 5'7:417-420. 1910. 
