1 54 Ethel McLennan and Isabel Cookson : 



by a distinct peridium [Plate IX., figs. 2 and 3 (p)]; it is composed 

 of large cylindrical asci and numerous paraphyses. 



The asci when young contain the ascospores grouped towards the 

 distal end of the ascus in a biseriate fashion [Plate IX., fig. 3 (s)], as 

 they become mature the spores are arranged in a monostichous man- 

 ner, they are 8 in number, globular, and alveolate in character [Plate 

 IX., figs. 4, 7], light brown at maturity and 34-36,^ in .diameter. The 

 asci turn blue with iodine, and are distinctly operculate. 



The paraphyses do not extend beyond the asci to any extent in the 

 ripe specimens; they are septate, swollen towards the apex, very often 

 branched, the two branches being equal [Plate IX., fig. 5], when old 

 they become brown at their apices and tend to shrivel. 



The sterile portion of the receptacle is composed of large pseudo- 

 parenchymatous cells without a well marked hypothecium, the ex- 

 tension of this sterile tissue in the form of a peridium can be seen 

 macroscopically, when fruiting bodies are cut in vertical section [Plate 

 IX., fig. 2]. 



The genus Sphaerosoma was founded by Klotzsch (1) in 1893, and 

 it has been the subject of much discussion. Uncertainty as to the 

 exact characters of the type species Sphaerosoma fuscescensy Klotzsch, 

 collected in the Grunewald, and also in the Botanical Gardens near 

 Berlin, led to many conflicting statements, and as a consequence much 

 confusion existed in regard to the members of the genus. In 1909, 

 Rouppert (2) published a revision of the genus Sphaerosoma, and this 

 was followed in 1910 by an exhaustive account of the genus by Setchell 

 (3). This paper includes the principal references to the genus and 

 its various species, so that it is unnecessary to deal with these in detail 

 here. 



As Setchell points out, Klotzsch figures his type specimen as 

 possessing echinulate spores, but describes them as verrucose in char- 

 acter. Later Corda (4) and Zobel (5) figured this species with tuber- 

 culate spores. As no type specimen had been preserved, much con- 

 fusion naturally arose. Setchell, after examining material of all the 

 species be could secure, and considering all the points in this mass 

 of conflicting ideas, states that " the weight of probability can hardly 

 prevail against the really convincing figures and description of 

 Klotzsch."! He therefore regards the echinate spore as characteristic 

 of the type, and considers that S. Janczewsklaiium, Rouppert, is prob- 

 ably identical with S. fuscescens, Klotzsch, as the spines on the spores 

 are short, rather than with S. echinulatum, as the spines on the 

 spores of the European (Rehm and Rouppert) and American (Seaver) 

 form of this latter species are longer and stouter. 



Setchell in comparing these echinulate-spored forms with others 

 described under the genus Sphaerosoma, shows that in addition to 

 their spore marking they are characterised by the possession of a 

 distinct peridium. In a young form of S. echinulatum, Seaver, the 



1. The writers are cognisant of a paper " Observations on Sphaero'soma 

 and allied genera," by J. F. Seaver (6), but follow Setchell (loc. cit.) in 

 preferring to accept Klotzsch's figure as expressing the cliaracters of the 

 type in the absence of an authentic type specimen. 



