390 BOTANICAL GAZETTE [NOVEMBER 
PILosTYLEs is a genus of the Rafflesiaceae parasitic upon various Leguminosae. 
Material from Brazil has been studied by ENprIss *7 in GOEBEL’s laboratory. 
The staminate flower consists of a solid axis in which are imbedded two circles 
of sporangia, with 18-20 sporangia in each circle, twenty being probably the 
usual number. If four sporangia represent one anther, the whole structure 
would represent five anthers, corresponding in some measure to the relations 
obtaining in the ovulate flower, which has normally five placentae. While the 
flowers are monosporangiate, a rudiment of the ovary appears as a column in the 
center of the staminate flower. In related forms the flowers are said to arise 
endogenously, within an originally compact tissue. In Pailostyles Ingae the 
flowers are strictly exogenous. The pollen grains are ext ly small, measuring 
only 5" in diameter. Some flowers have been pollinated, but in only one case 
had pollen tubes begun to form. Many older seeds contained embryos, but no 
trace of pollen or pollen tubes could be found. The writer doubts whether normal 
fertilization occurs. The anatomy of the plant and the development of the 
embryo are described.—CHARLES J. CHAMBERLAIN. 
Various ATTEMPTS have been made to attribute to external conditions the 
polarity seen in cuttings of roots and shoots. The latest effort is by Kuster, 
who discusses in a preliminary paper'® the influence of oxygen and of centrifugal 
force upon polarity, and in a second *° enlarges upon the same topic. KUsTer 
placed the roots of Taraxacum, which under uniform conditions of moisture 
produce roots at the apical (normally lower) end and shoots at the basal end, 
with their basal (normally upper) ends in water and the opposite ends pointing 
upwards into the air. Shoots develop on the latter end and none on the parts 
water. Cuttings of the stems of Ribes aureum placed with their basal ends in 
water and their apical ends in moist air produced roots only on their apical ends. 
Salix vitellina gave similar results, showing a marked tendency for the roots #9 
appear only where there is a sufficient supply of air. Cuttings of Salix and other 
plants were rotated horizontally on a centrifuge. The centrifugal force acted as ; 
check upon development, the inhibition being in proportion to the force, 1. @ 
the apical end describe the greater circle the buds there are inhibited more than 
those at the opposite end. In this way the usual polarity may be reversed.— 
W. B. MacCatium. 
Lyon?° has made a detailed and much-needed study of the embryogeny . 
Ginkgo, with an unusual abundance of illustration. The general panasgeel 
mass of tissue that is known to fill the egg after free nuclear division 1S 
; Ulei 
NDRISss, W., Monographie von Pilostyles Ingae (Karst.). (P ilostyles 
weE 
Solms-Laub.) Flora 91: 209-236. pl. 20. figs. 3I- 1902. Spross- 
18 Kuster, Ernst, Experimental Untersuchungen iiber Wurzel- und i 
bildung an Stecklingen. Ber. Deutsch. Bot. Gesells. 22: 167-179- ste ae 
to Kuster, Beitrige zur Kenntnis der Wurzel und Sprossbildung 2” " 
Jahrb. Wiss. Bot. 40: 279-302. figs. 4. 1904. . 
20 Lyon, Harotp L., The embryogeny of Ginkgo. 
290. pls. 29-43. 1904. 
Minn. Bot. Studies 3: 275~ 
