156 BOTAXICAL GAZETTE [august 



While KvsTER confirms Haberl.\ndt's obsen^ations that the nucleus is usually 

 near the tip of the rhizoid in many plants, he finds that in Hydrocharis morsus- 

 ranae, and in many other plants of similar habitat, the nucleus is Just as constantly 

 at the base of the root hair. The suggestion is made that the position of the 

 nucleus in root hairs may be a result of growth rather than a cause of it, or the 

 position may be due to unknown factors. 



In regard to the position of nuclei in the stomatal apparatus, Kuster is 

 inclined to believe that the position of the nuclei of the neighboring cells is not 

 related to the development of the guard cells, but rather that the position near 

 the concave wall is due to physical factors which favor or compel this position. 

 In many plants, like Osmundaregalis, when the neighboring cells are not crescent- 

 shaped, the nuclei are not situated near the walls. 



Although Kuster agrees with Haberlandt that the nucleus is often found 

 at the place where local thickenings of the cell wall are taking place, he also finds 

 other instances where the nucleus is not so situated. 



In these three classes of phenomena, Kuster regards HABERLA>rDT's explana- 

 tions as teleological. He himself, however, is not able to find a satisfactory 

 explanation for the varying position of nuclei and he believes that the factors 



which determine it have not yet been discovered. — Charles J. Chamberlain". 



w 



Items of taxonomic interest.— J, N. Rose (Smithson. Quarterly 50^32- 

 1907) has made additions to his synopsis of the Mexican species of Ribes and 

 has described a new species; has proposed, in connection with J. H. Painter 

 {idem 33-34), the new generic name Morkillia for Chitonia M05. and Sesse 

 (Zygophyllaceae), which is a homonym of Chitonia D. Don.; and has described 

 {idem 63-64. pi, 6) a new Cactus from Guatemala, a species of the Melocactus 



■N. Patoijillard 



(Bull. Soc. Mycol. France 23:50-52. 1907) has described a new genus {Le 

 Ratio) of hymenogasters from New Caledonia. — H. Harms (Bot. Jahrb, 40: 15-44- 

 1907), in his fourth paper on African Leguminosae, has described a new 

 genus, Englerodendron.—R, Hamet (Bull. Soc. Bot. France 54:26-38, 52-76. 

 pL 2. 1907) has published a synopsis of the genus Drosera, recognizing 65 species, 

 setting aside 4 as insufficiently known, and excluding 7. — S, Brown (Torreya 

 7:125, 126. 1907) has described a new spruce {Picea alberiiana) from the Canad- 

 ian Rocky Mts., which had been referred to both P. canadensis and P. mariana, 

 A, Zahlbruckner (Ann. K. K. Naturh. Hofmus. 20:350. 1907), in centuries 

 xii and xiii of his Kryptogamae exsiccatae, publishes a new lichen {Rinodina 

 iowensis) from granite rocks near Fayette, Iowa,— J. M. C. 



Vegetation in Somerset, England.— Following the lead of the late Robert 

 Smith, vegetation maps are multiplying in England. The latest is that of the 

 Bath and Brideewater district of Somerset, and is the work of C. E. Moss.^^ 



proposes 



14 Moss, C. E., Geographical distribution of vegetation in Somerset: Bath and 

 Bridgewater District. Publ. Roy. Geog. Soc. London." pp. 71. figs. 24. colored map. 

 1907. 



