* 



* 



I 



1907] CURRENT LITERATURE 237 



The writer several tiraes divided colonies of P, intermedium and of P. rostralumy 

 keeping one -half of each colony in running water while the other half was left 

 undisturbed. The half-colonies in running water produced almost exclusively 

 sporangia, while the corresponding undisturbed halves produced conidia. In 

 the systematic part of the work, 18 species are critically described and arranged. 

 Four of these are new, one (P. palmivorum) being of interest on account of its 

 unusual habitat, growing in the terminal buds of palms which are soon killed and 

 destroyed by the fungus. Since palms grow only by the terminal bud, its death 

 involves the destruction of the tree. Another form (P. Indigojerae) is epiphytic 

 in the waxy covering of the leaves of Indigofera arrecia. Under the title *' Species 

 omitted" there are added brief notes on some 18 species whose descriptions are 

 for the most part so fragmentary that identification is impossible. In the second 

 part, a number of species of Chytridiaceae are described, with some observations 

 on their structure and habits. — H. Hasselbring. 



■- 



Anatomy of Uvularia and Tricyrtis. — QuEVA^^ has followed his studies on 

 Gloriosa and Littonia by an examination of the anatomy of Uvularia and Tricyrtis, 

 which differ from the first-named genera in having a rhizome in place of a tuberous 

 stem. In accord with this difference, Uvularia presents a simpler structure than 

 Gloriosa, and Tricyrtis is still simpler in the disposition of its vascular strands. 

 The bundles in the stem of Tric}Ttis are all of the same rank, while Uvularia has 

 bundles of several ranks; the larger ones are situated near the center of the stem 

 and form the main vascular strands of the leaves, while the smaller ones run at 

 the peripher}' of the stem and run to the margin of the leaves. In place of the 

 cambium observed in the bundles of the tuber in Gloriosa, Uvularia presents only 

 a radial arrangement of the cells of the procambial strands. These two conditions 



distinguished 



MAN and by Chry 



M. A, Chrysler. 



in the bundles of sedges and grasses, figured by Plo 

 The question appears to be one of definition of terms. 



The nucleus of Spirogyra.— The excellent methods and cytological experience 



Gr£goire school are w^ell shown 



Both the 



chromatic and the achromatic figures are traced in detail. The so-called nuclear 

 network of Spirogyra takes no part in the formation of chromosomes. In the 

 prophase the nucleolus begins to show a double nature, for the chromosomes are 

 differentiated within itj while a second substance preser\-es its spherical form. This 

 second substance divides m the plane of the future cell wall and also becomes 

 segmented into rod-shaped pieces, after which half passes ' 



pole to form 



formed 



^4 QuEVA, Chas., Contributions a Tanatomie des Monocotyledonecs. II. Les 

 Uvulari^es rhizomateuses. Beih. Bot. Centralbl. 22:30-77. figs. 40. 1907. 



15 Berghs, Jules, Le noyau et la cinese chez le Spirogyra. La Cellule 23 :S5~86, 

 pis, I- J. 1906. 



