ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 169 



cause, or where the parts are put iu liquid nutrient media, there is a 

 strong tendency for the spores to be retained in the sporangium, or, if 

 discharged, for them to sprout at once without a second swimming 

 stage." The author has compared a large number of species of various 

 allied genera with reference to the escape of the spores. He linds in 

 the species he has cultivated that the spores are discharged by internal 

 pressure and not through their own motion. 



Haustoria of Meliola and Asterina.* — CI. Arnaud alludes to the 

 work of Maire, who proved that the fungi of these genera were parasitic 

 on leaves, and withdrew nourishment from the host by means of 

 haustoria somewhat like those of the Erysiphacese. The haustoria are 

 generally the terminal cells of the hyphopodia. They pierce the cuticle 

 of the epidermis at the junction of two cells, and are at first intercellular. 

 In Meliola the haustoria are generally simple ; occasionally the surface 

 bears small projections. In Asterina they form digitations which in- 

 crease the amount of surface. The haustoria of A. clavispora are 

 spherical with a clearly defined double wall ; the lower part produces one 

 or more filaments which pierce the cell and form here and there unilateral 

 swellings. In another species, A. anonicola, a pseudo-parenchyma is 

 formed which fills the cell. A comparison is made with other genera. 



In a second paper, f Arnaud examines the haustoria in the genera 

 Balladyna, Lembositt, and Parodiopsis. Those of Balladyna, which 

 resemble Asterina in being branched, traverse the cuticle of the epidermis 

 and occupy the walls of the host-cells, they thus form " digitations " 

 which are the haustoria, and which push inwards the internal layer of 

 the cell-wall. The haustoria of Lembosia are more varied and follow 

 various types, mostly they are branched filaments. Parodiopsis has a 

 superficial mycelium and perithecia. The mycelium forms one or two 

 large filaments which enter the host by the stomata and ramify, forming 

 intercellular hyphse which bear haustoria. 



Aleuria and Aleurina.J — F- J- Seaver gives an account of the 

 American species of these genera of Discomycetes. They are both dis- 

 tinguished by the reticulate character of the spores, but those of Aleura 

 are colourless, while those of Aleurina are coloured. The best known 

 species of Aleuria is the brightly coloured A. aurantia. That and 

 the three other American species are of an orange-yellow colour, and are 

 all of them European as well as American. Two species of the new 

 genus Aleurina are described ; one of them a new species, being found 

 as yet in America only. 



Thelephoracese of North America. § — E. A. Burt continues his 

 work on this family of Fuugi. The present paper mainly deals with the 

 genus i 'yphella, but it also includes the description of a rare species 



* Comptes Rendus, clix. (1914) pp. 807-9. 



t Comptes Rendus, clix. (1915) pp. 180-3. 



% Mycologia, vi. (1914) pp. 273-8 (3 pis.). 



§ Ann. Miss. Bot. Gard., i. (1914) pp. 357-82 (1 pi.). 



April list, 1915 N 



