96 SUMMARY OF CURRENT RESEARCHES RELATING TO 



r " Formation of the Teleutospore in Puccinia.* — M. E. Maire describes 

 the cytological phenomena which precede or accompany the formation of 

 the teleutospores in Puccinia Liliacenrum. In the terminal cells of the 

 filaments which produce the teleutospores, the division of the nucleus is 

 not followed by septation ; these cells are therefore binucleated. A 

 nucleole or plasmosome makes its appearance in each nucleus, and 

 gradually increases in size. The safranophile chromatin disappsars, or 

 is transformed into an acidophil substance, but not identical with the 

 substance of the plasmosome. At the time when the teleutospore is 

 formed, the nucleus has become entirely acidophil ; and after the fusion 

 of the two nuclei, the resulting nucleus is still acidophil. The cell 

 which constitutes the pedicel of the teleutospore has gradually lost its 

 protoplasm, which has passed into the teleutospore itself. While the 

 increase in number of the cells of the mycele takes place by amitotic 

 divisions, the teleutospores themselves ai'e formed by mitosis. 



Myxoroycetes. 



Comatricha obtusata.f — Herr E. Jahn finds this Myxomycete on 

 branches of fir, less often of oak. The sporanges resemble those of 

 Stemonitis, but are solitary, not collected on an expanded hypothallus ; 

 they have a hollow pedicel which is not twisted. The young sporanges 

 appear in the form of milk-white drops on the wood. The capillitium 

 begins to be formed before the pedicel is fully developed. The author 

 holds that the nucleus takes no part in the formation of the membrane. 



Macbride's North American Myxomycetes.J — Dr. T. H. Macbride 

 publishes a monograph of the North American species of Myxomycetes 

 (including Central America), prefaced by an account of the structure 

 and life-history of the group. The number of species described is about 

 200, of which a very few are new. The genus Plasmodiophnra is first 

 separated as the sole North American member of the sub-class Phyto- 

 myxinae, distinguished by its parasitic habit. The saprophytic Myxo- 

 mycetes are then divided into the Exosporese with free spores, and the 

 Myxogastres in which the spores are contained in receptacles or 

 sporanges. The first group comprises the single genus Ceratiomyxa ; 

 the second group is again divided into five orders — the Physaraceao r 

 Stemonitacere, Cribrariacete, Lycogalacese, and Trichiacese. 



Protophyta. 

 #. Schizomycetes. 



Structure of Bacteria.§— Mr. S. Rowland, who has made some inter- 

 esting observations on the structure of bacteria and the embryology ot 

 the spore, states that in the actively living cell, i.e. one which is about 

 to divide, or has just divided, no reticular structure can be demon- 

 strated. An organism in which structure is visible is not an actively 

 living cell, but is progressing either to spore-formation or to granule- 



* Coniptes Kendua, exxix. (1899) pp. 839-41. 



t Festschr. f. Schwendener, 1899, p. 288 (1 pi.). See Bot. Centralbl., lxxix. (1899) 

 p. 252. 



% s The North American Slime-Moulds,' New York, 1899, xvii. and 233 pp. and 

 19 pis. 



§ Trans. Jenner (late British) Inst. Prevent. Med., 1899, ser. ii. pp. 143-60 (1 pi.). 



