256 BOTANICAL GAZETTE [MARCH 
in a manner similar to that of the organism of Myrica described above. Miss 
SPRATT also finds that under certain conditions, both in the root and in cultures, 
the organism gives rise to relatively large spherical bodies or coccus forms. 
This polymorphism seems to be the result of lack of nutrition. When nutri- 
ment is supplied they divide and become transformed into typical bacilli. It 
was also shown that the organisms from both plants were capable of fixing free 
nitrogen, thus confirming HILTNER’s observations.—H. HASsELBRING. 
Morphology of orchids.—VERMOESEN” has made a careful study of the 
development of the ovule in several orchids. He finds arising at the lines of 
fusion of the three carpels three longitudinal “primary placental protu- 
berances,”’ each of which is caused by the cailgaict: of a band of subepidermal 
tissue, usually appearing in cross-section as three cells (possibly from a single 
The lateral members of this band of cells continue to divide actively, 
in the median line growth is retarded, resulting in a bifurcation of the 
placental protuberance. Growth is further checked at various transverse 
levels, so that the ovary wall soon shows three double rows of small promi- 
nences, each with its isolated group of active subepidermal cells. These promi- 
ces now branch repeatedly to form the numerous ovulary filaments, each 
of which finally produces an ovule at its summit. All the steps of this process 
are initiated by the activity of the subepidermal cells, which retain the charac- 
ters of archesporial tissue 
The author’s main conclusion is that the primary archesporial cells are 
those which give rise to the original placental protuberance on the wall of the 
ovary, since this group of cells by repeated dichotomy gives rise to all the 
tissue within the branched placenta, funiculus, and nucellus. The steriliza- 
tion idea is extended to include all these organs. It is further held that each 
carpel originally produced on its ventral surface two marginal archesporial 
bands which have become fused with those of the neighboring carpels. 
The development of an eight-nucleate embryo sac from one megaspore 
of an “incomplete tetrad” and fertilization occur in the usual manner.— 
STER W. SHARP 
Dioecism in Epigaea.—The flowers of Epigaea repens were divided by 
Gray into two main groups: one with well developed stigmas and abortive 
stamens, and the other with small, poorly formed stigmas and well developed 
stamens. Both groups possess equally good ovaries and ovules, and both 
show stamens and pistils of various lengths. STeEvENs™ has undertaken to 
determine two points: (1) whether there is any real evidence of a heterostylic 
condition, and (2) whether the species is actually dioecious. He finds that 
10 VERMOESEN, CAMILLE, Saree a l’étude de l’ovule, du sac embryonnaire, 
et de la fécondation dans les angiosperm La Cellule 27: 115-162. pis. 2. 1911. 
11 SrevENS, NEIL E., Dioecism in sags trailing arbutus, with notes on the mor- 
phology of the seed. Bull. Torr. Bot. Club. 38: 531-543. jigs. 4. 1911. 
