80 BOTANICAL GAZETTE [JANUARY 
Morphology of Parthenium.—P. argentatum has become notable as the 
“guayule,’’ or desert rubber plant, which is being exploited extensively in 
Mexico. In connection with its investigation for economic purposes, KIRK- 
woop” has investigated its life history, and also that of P. incanum and P. 
hysterophorus. It appears that in the guayule about 17 per cent of the seeds 
contain embryos, the numerous failures not being due to failure in fertiliza- 
tion, “but apparently to the cutting off of the nutritive supply in the later 
stages of development.”’ The structures of the embryo sac, the development 
of the embryos, and spermatogenesis all seem to conform to the situations 
usual among Compositae.—J. M. C 
tructure of alpine plants.—A very considerable amount of asymmetry 
has been found by Brocu” in the underground stems of certain alpine plants, 
notably in the rootstocks of Anemone baldensis and Bartsia alpina, the latter 
aving a woody cylinder eight times as thick on one side as on the other. 
Among other peculiarities of these plants, the rootstock of Geum reptans is 
shown to have a cambium layer in the pith, and the older roots of two species 
of Campanula to develop an abnormal amount of lacunar tissue. An explana- 
tion of these phenomena will be sought in experimental studies.—Geo. D. 
FULLER. 
Cretaceous conifers of Japan.—JEFFREY™ has called attention to the strik- 
ing resemblance of the cretaceous coniferous flora of Japan, as recently described 
y Stopes and Fuju, to that of the Atlantic seaboard of North America. 
The resemblance is perhaps closer than the authors suspected, for JEFFREY 
claims that their proposed new genus Vezonia is in reality his Rane 
and that their Cry tl —J.M.C. 
f Lil! MAALIG AS LI ae 
Establishment of the giant cactus.—From measurements of plants of vari- 
- ous ages and a careful study of areas near Tucson, Arizona, containing several 
hundred individuals, SHREVE” concludes that the giant cactus (Cereus gigan- 
teus) is not maintaining itself. No sufficient reason for this decadence is yet 
known. ‘The average expectancy of life for this cactus in the Arizona desert 
seems to be about 175 years.—Gero. D. FULLER 
*» KrrKwoop, J. E., The life history of Parthenium (guayule). Amer. Rev. Trop- 
Agric. 12193-205. pls. 11-13. 1910 
20 BLocH, MapAME. E., Sur as anomalies de structure des plantes alpines. 
Rev. Gén. Bot. 22: cies. IgIo. 
at JEFFREY, Epwarp C., On the affinities of the genus Yezonia. Annals of Botany 
24:767-773. pl. 65. 1gto. 
22 SHREVE, Forrest, The rate of establishment of the giant cactus. Plant World 
I13:235-246. I910 
