536 SUMMARY OP CURRENT RESEARCHES RELATING TO 



5. Some cortex-tubes develope one secondary cell only, which 

 becomes as long as the primary cell, but is of smaller diamet3r (0. 

 excelsa Allen, G. intermedia A. Br., G. contraria A. Br. Sect. Tyla- 

 canthse). 



6. Some develope only one lateral cortex-cell, which becomes 

 larger than the primary cell and partially covers it, so that the 

 primary cell seems to lie in a furrow {G. fcetida A. Br. Sect. Aula- 

 canthse). 



7. Some cortex-cells develope perfectly one lateral cell, and im- 

 perfectly another (G. aspera Willd.). 



8. Some cortex-cells develope perfectly both lateral cells, so that 

 three complete series of cells arise from each leaf (0. fragilis Desv., 

 G. gymnopus A. Br.). 



Details of the application of these characters are followed by full 

 descriptions of the following new American species : — G. inconnexa, 

 evoluta, and excelsa. 



Fungi. 



Ustilaginese.* — The fifth part of De Bary and Woronin's ' Morpho- 

 logy and Physiology of Fungi' is occupied by a treatise on the 

 Ustilaginese by M. Woronin. 



The first section consists of a complete life-history of Tuburcinia 

 Trientalis Berk, and Br., which attacks the stem, leaves, and rhizome 

 of Trientalis europwa. The mycelium consists of sparingly septated 

 and irregularly branched hyphas which permeate the intercellular 

 spaces, and put out haustoria! lateral branches into the cells them- 

 selves of the host ; these branches, with their short irregular secondary 

 branches, having somewhat the form of a bunch of grapes. On this 

 mycelium are produced two kinds of reproductive organ, conidia and 

 resting-spores. The conidia are always borne on the under side of 

 the leaves of the host, and form a white mould-like coating, the 

 Ascomyces Trientalis of Berk. The hyphse on which they are borne 

 form a more or less dense felt between the epidermis and the meso- 

 phyll ; lateral branches then penetrate through the stomata or between 

 the walls of the epidermal cells, and bear the pear-shaped conidia, 

 either first putting out haustoria or not. The conidia germinate 

 readily in water, putting out a germinating filament, which either at 

 once developes a conidiophore, or continues to grow without putting 

 out conidia. Conidial hyphse are also produced by sowing conidia on 

 moistened leaves of Trientalis. These give rise to small patches of 

 mycelium, on which the resting-spores are developed. 



The resting-spores form brown Sorosporium-like masses, dusky 

 patches ij-2 mm. in diameter, on the leaves and leaf-stalk of the host. 

 These spores are produced on much-branched mycelial filaments, 

 which appear usually to be of smaller diameter than the purely vege- 

 tative ones, to be more freely septated, and usually destitute of 

 haustoria. In their youngest stage they have the form of straight or 

 curved, spiral or twisted branches,, either singly or in coalescent 



* De Bary, A., u. Woromn, M., ' Beitrage zur Morph. u. Phys. tier Pilze,' Part v. 

 35 pp. (4 pis.), 4to, Frankfurt a. M., 1882. 



