146 BOTANICAL GAZETTE [FEBRUARY 
Tetrads of a Drosera hybrid.— RosENBERG"' states that in the genus Drosera 
the pollen cells remain united in tetrads at maturity, even after pollination. 
In the hybrid D. rotundifolia D. longifolia, in which he previously studied 
the earlier stages of pollen development,?? he now describes the mature stage after 
the reduction division. Instead of four pollen cells in such a tetrad, he finds 
occasionally in the hybrid additional small pollen grains, which arise from extra 
nuclei formed by chromosomes left behind in the cytoplasm during the reduction 
divisions. The tetrad groups of the parent species are distinguishable by the 
size and shape of their individual grains, those of D. rotundifolia being smaller 
and rounded at the outer edge, those of D. longifolia larger and flattened. In 
most of the tetrads of the hybrid containing only four pollen cells, all the grains 
_ have the size and shape of D, longifolia; but occasionally two cells have the 
characters of one parent and two those of the other. He concludes that in the 
distribution of chromosomes in the reduction divisions, chromosomes from both 
parents usually enter all the daughter nuclei, but that occasionally in the first 
division the chromosomes of D. rotundifolia are more or less completely segre- 
gated from those of D. longifolia, two of the pollen cells of such a tetrad having 
the characters of the pollen of each parent.—R. R. GarTEs. 
Items of taxonomic interest—S. H. Burnuam (Torreya 6:235. 1906) has 
described a new Monotropsis from the Blue Ridge Mountains.—W. H. 
CHARD (idem 236) has described a new Rubus (dwarf blackberry) from Ver- 
mont.—B. F. Busm (Rept. Mo. Bot. Garden 119-125. 1906) has described new 
Texan species under Tracyacanthus, Allium, Psoralea (2), Tragia, Xanthium 
Antennaria, and Silphium.—A. S. Hircacock (Rhodora 8:205-212. 1906), 
among notes on yrasses of the N. E. United States, describes new species in Pani- 
cum (4) and Glyceria—W. H. BLancuarp (idem 212-218) describes 2 new 
species of Rubus (blackberries) from Maine—A. BERGER (Notizblatt 4: 250. 
1906) has described a new Agave from Mexico.—H. H. Harnes (Jour. Linn. 
Soc. 37: 407-409. 1906) has described 2 new species of Populus from India.— 
O. Stapr (idem 495-532), among descriptions of numerous new species from the 
Dawe’s collection from Uganda, publishes the new genus Blasamocitrus (Rutaceae). 
—J. Huser (Boletim Mus. Goeldi 4: 510-619. 1906), in his sixth contribution 
to a flora of the Amazons, describes Browneopsis as a new genus of Leguminosae 
(Caesalpinioideae). J.C. ArTHUR (Journal of Mycology 13:28-32. 1907) has 
published Polioma, Spirechina, Prospodium, and Nephlyctis as new genera of 
Uredinales—Pu. VAN Tr1GHEeM (Ann. Sci. Nat. Bot. IX. 4:223-260. 1906) 
has established the new dicotyledonous family Agialidaceae, to include 
certain spiny trees and shrubs referred usually to Balanites (Simarubaceae), the 
at ROSENBERG, O., Erblichkeitsgesetze und Chromosomen. Botaniska Studier, 
tillignade F. R. KJELLMAN 1906:237-243. jigs. 5. 
, Das Verhalten der Chromosomen einer hybriden Pflanze. Ber. Deutsch. 
Bot. Gesells. 21:110. 1903.—Uber die Tetradentheilung eines Droserabastardes. Ber. 
Deutsch. Bot. Gesells. 22:47. 1904. 
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