478 BOTANICAL GAZETTE [JUNE 
follows: the embryo does not penetrate the endosperm mechanically, by means of 
the elongating suspensor, but probably by the secretion of an enzyme; it grows 
for a time by means of a true apical cell, which later is replaced by a group of 
initials; after this, the most active growth is at the proximal end of the embryo, 
first differentiation being the root periblem, the cotyledons and stem tip 
appearing later. It is an interesting fact that the species produces only two 
archegonia. 
The seasonal differences between Cape Colony and the northern hemisphere 
in reference to the development of structures are very interesting. Pollination 
occurs during the winter; the ovule is in the resting stage during the late summer 
and autumn; pollination and fertilization are separated by 14-15 months (12-13 
in England, ete.); the archegonia mature more slowly, the central cell persisting 
for at least three weeks (as compared with one or two weeks).—J. M. C. 
Capsella Bursa-pastoris and C. Heegeri.—The relation of Capsella H. i 
discovered growing wild in Germany ten years ago, to the cosmopolitan C. Bursa- 
pastoris has been in question. Its appearance in a region whose plants are so 
well known suggested its recent origin by mutation, and in that case the parent 
plant should be C. Bursa-pastoris. SHuxi4° conducted a series of cultures and 
reported the results at the Boston Meeting of the International Zoological Con- 
gress in 1907, and the report has just now appeared as an advance print from the 
Proceedings! The matter is old, but this publication of it may be noted. The 
results showed that C. Heegeri has the same Mendelian units in its leaves as occur 
in C. Bursa-pastoris; that the crossing of the two species gives rise to correspond- 
ing series of elementary species; that leaf characters are inherited in strict Mende- 
lian ratios, but the capsule shows a very great departure; and that the capacity of 
C. Heegeri for self-maintenance in competition with C. Bursa-pastoris rests 
upon the comparative infrequency of cross-fertilization—J. M. C 
4° SHULL, GEORGE H., Results of crossing of Bursa bursa-pastoris and Bursa 
Heegeri. Advance print from Proc. 7th Internat. Zool. Congress. pp. 6. 19109. 
