162 Morphologie, Befruchtung, Teratologie, Cytologie. 



Barratt, J. O. W., The Staining Act: an Investigationinto 

 the nature of methyleneblue-eosin staining. (Biochemical 

 Journal, Vol. I. Nos. 8 and 9. 1906. p. 406—428.) 



Three views as to the nature of staining are held : (I) That it is 

 a Chemical reaction between stain and cell; (II) that the dye is adsorbed; 

 (III) that the dye is present in the State of solid Solution in the stained 

 material. 



The author concludes that the staining act of methyleneblue 

 eosin in alcoholic Solution is a chemical reaction. The Solution in 

 water or alcohol exhibits coUoidal properties as do also methylene- 

 blue, and eosin in their water-soluble and alcohol-soluble tbrms. 



E. Drabble (Liverpool) 



Bessey, C. E. Two and three pistils in Cassia Chamaecrista, 

 (Science N. S. XXIV. 572. November 2, 1906). 



The abnormality is viewed in the light of reversion to a poly- 

 carpellary ancestral type. Trelease. 



Blackman, H. V. and Helen C. 1. Fräser Further Studies on 

 the Sexuality of the Uredineae. (Ann. Bot. XX. Jan. 1906. 

 p. 35—47. 2 plates.) 



Various types of nuclear migrations were found. In Uromyces 

 poae Rabenh. there is a migration of a nucleus from a vegetative 

 cell to a fertile cell. The migration is more difficult to observe than 

 in the case of Phraginidüitn violaceiini for the fertile cells are neither 

 well defined, nor can progressive stages be observed in passing from 

 the periphery of the aecidium to the centre. 



Puccinia poarinn Nies. Migrations of the same type occur, i. e. 

 fertile cells are diiferentiated and a nucleus passes into these from a 

 vegetative cell. Cases were observed of the migration of a nucleus 

 from one vegetative cell to another. This is held to be fertilization 

 before the differentiation of the female cell. 



In Melatnpsora Rostrnpi Wagn. the fertile cells fuse in pairs 

 with each other, in the same wa}'^ as Christman showed for Caeotna 

 nitens. A definite row of large uninucleate fertile cells, with sterile 

 cells above, is developed close beneath the epidermis. Fasing of the 

 partition walls was observed but no actual nuclear migrations. The 

 cells of the aecidium produced in this way can no longer be called 

 "fertile cells" since they are the product of two such cells; the term 

 "basal cells" is therefore suggested. 



Puccinia malvacearntn Mont. is a lepto-form which maj" complete 

 its life-cycle in 15 days. The vegetative mycelium is uninucleate; 

 the binucleate stage arises amidst the mass of hyphae at the base 

 of the young teleutospore sorus. Nuclear migrations were not 

 observed but presumably they occur in the same manner that thej^ 

 do anomalously in Ptic. poarinn. 



In Puc. adoxae DC. and Uromyces SciUannn Wint. the general 

 vegetative mycelium is binucleate. Migration of nuclei probably 

 therefore takes place very early, soon after the germination of the 

 sporidium. 



Uromyces Ficariae Lev. is apparently intermediate between P, 

 ■malvacearutn and P. adoxae. 



