292 BOTANICAL GAZETTE [ APRH. 
The genus belongs to the Monimiacez, and is peculiar to tropical America, 
with its greatest development in southern Brazil. In 1868, in his monograph 
of the genus for the Prodromus, A. DeCandolle recognized 28 species, two of 
them being regarded as doubtful. In the present — - species are 
presented, 46 of them being described for the first time.— J. M 
A REVISION of the North American species of Euphorbia ee Tithymalus 
has been published by J. B. S. NorTON in the 11th annual report of the Mis- 
souri Botanical Garden, illustrated by 42 plates. Thirty-six species are rec- 
ognized, eight of them introduced from Europe, and one of them new. The 
section contains about 400 species of the 700 or more that have been 
described, but is rather poorly represented in America, the greater number 
being southwestern and xerophytic.— J. M. C 
NOTES FOR STUDENTS. 
MR. FRANCIs E. Lioyp is making a vigorous study of the comparative 
embryology of the Rubiacee. His first paper? outlines the task before him 
and discusses the development of Vazllantia hispida, one of the Galiex 
indigenous to the Mediterranean region, from earliest stages to mature fruit, 
paying special attention throughout to the matter of nutrition. The chief 
characteristics of this species are: a multicellular archesporium; a single 
integument; migration of the megaspore mother cell and development in the 
micropyle ; great development of antipodals for the sake of securing food to 
the growing embryo-sac, and the development of a suspensor with cells 
clustered like a “bunch of grapes,” which breaks down with the appearance — 
of the cotyledons. There is found an abundant source of food supply and an 
efficient means of transmitting it during every stage of development, until 
finally the plant by way of the vascular region deposits a supply of starch 
and cellulose in the tissues surrounding the mature embryo.—J. E. WEBB. 
BARANETZKY, to whom we owe an improved form of the registering 
auxanometer, describes” a new apparatus for recording the periodic curva- 
tures of leaves and stems. The registering apparatus itself consists of a 
drum, carrying smoked paper, and rotated by clockwork once in twenty four 
hours. The writing point, a bit of flexible metal, is attached to a vertical 
belt, longer than the drum, passing over pulleys actuated in seg direc- 
tions by one or the other of two electromagnets on the bas The leaf 
stalk or stem to be studied is fastened to a swinging lever wide actuates a 
train of three wheels by which the movements are magnified. The third 
axle carries a spur wheel, which, by bending aside a flexible platinum strip, 
»LLoyp, F. E.: The comparative embryology of the Rubiacee. Bull. Torr. Bot. 
Club 8: 1-25. f/. 7-3. 1899. 
* Berichte d. deutsch. bot. Gesells. 17: 190. 1899. 
