680 SUMMARY OF CURRENT RESEARCHES RELATING TO 



becomes detached by the shrinking of its basal cells, and the appendages 

 then serve to bring about its attachment to a secondary substratum. The 

 author regards the genus Sphserotheca , with its single ascus and appendage, 

 and the absence of a differentiation of the wall of the perithece into an 

 upper and under side, as the ancestral type of the order. From this is 

 derived Erysiphe, characterised by numerous asci and a usually simple 

 appendage ; the other genera exhibiting greater complexity of structure. 

 "With regard to the structure of the perithece, the Erysipheaa may be 

 classified under two heads : — (A) Peritheces not falling off spontaneously, 

 usually attached to the mycele by the appendages (Sphserotheca, Erysiphe, 

 Uncinula circinata ?) ; (B) Peritheces falling off when ripe. These latter 

 are again classified under two subdivisions : — (1) Detachment caused by 

 the shrinking of the base of the perithece (Podosphsera, Trichocladia, 

 Microsphsera, Uncinula section Microsphaeroidea, and section Euuncinula 

 except U. circinata) ; (2) Detachment of the perithece by the pressure of 

 the appendages against the substratum (Phyllaetinio). 



Arsenic Fungi.* — B. Gosio has paid special attention to the group 

 of Fungi which have the property of decomposing compounds of arsenic, 

 with production of the peculiar garlic-like odour of arsenious acid. Of 

 these Penicillium brevicaule was specially studied. Independently of its 

 production of volatile compounds of arsenic, this fungus is pathogenic 

 to rabbits, producing pneumonia. The author discusses the use of this 

 fungus as a test for arsenic, in the production of the garlic-like odour. 

 As a nutrient material, potato is preferable to bread. It produces alco- 

 holic fermentation, and inverts starch. 



Coprophilous Fungi, f — G. Massee and E. S. Salmon describe a 

 number of new species belonging to the Ascomycetes saprophytic on the 

 excrements of a variety of different animals (mammalia and birds) ; also 

 two new genera, viz. : — 



Pleuroascus g. n. (Perisporiaceas). Perithecia subiculo intexto pan- 

 noso distincto v. confiuente insidentia, atra, astoma, membranaceo- 

 carbonacea, fragilia, contextu parenchymatico, appendicibus pluribus 

 hyalinis arete spiraliter convolutis instructa ; ascis globosis, minutis, 

 numerosissimis, mox diffluentibus, in hyphis ramosis pleurogenis ; sporis 

 minutis, fuligineis, globosis. 



Spumatoria g. n. (SphaeriaceaV). Perithecia subglobosa, semi-iinmersa, 

 demum superficialia, membranacea, in rostrum longum cylindraceum 

 apice fimbriatum plus minus dilatatum attenuata ; ascis tenuibus, 

 evanescentibus, octosporis, sporis didymis, hyalinis ; demum in spuma 

 mucilaginosa ex ore rostri ejectis ; paraphysibus indistinctis. 



The majority of coprophilous fungi occur on the excrement of 

 herbivorous animals, and they are propagated by the spores passing 

 through their bodies rather than by the wind; as a rule' any one sj)ecies 

 of fungus is not confined to the excrement of a single animal. In species 

 of Ascobolus, Byparobius, Saccobolus, Sordaria,SLXi& Thelebolus, the spores 

 are ejected at maturity in an agglutinated mass, often to a considerable 

 distance. This ejection occurs equally in bright sunshine and in dark- 

 ness. The sudden shooting-out of the spores appears to depend on the 



* 11 Policlinico. 1900, No. 10. See Bot. Oenhulbl , Ixxxvii. (1901) p. 131. 

 t Ann. of Bot., xv. (1901) pp. 313-57 (2 pis.). 



