376 SUMMARY OF CURRENT RESEARCHES RELATING TO 



and Dicrmmm are distinguislierl by containing a large amount of oil. 

 Mnium contains 10 per cent, of sugar ; the proportion decreases 

 successively in CUmaciiim, PolytricJium, Hypnum, Dicranum. Sphagnum, 

 Orthotriclium, Schistidium, and Ceratodon. Albumen occurs abundantly 

 in the protoplasmic cells of the leaves ; Ceratodon purpureus contains 

 12, Polytrichum 5 per cent. ; but it is not in a condition serviceable 

 for the nutrition of animals. 



Fungi. 



Influence of Oxygen on the Development of the Lower Fungi.* 

 — F. Hoppe-Seyler states, as the result of a careful series of experi- 

 ments, that an excess of oxygen greatly promotes the development of 

 bacteria and micrococci, while it exerts a retarding influence on the 

 production of yeast and true ferments, hindering fermentation by the 

 transformation of the organic substances which ordinarily result from 

 it, by active oxidation, into carbonic acid, water, and ammonia. 



Chsetomium.t — W. Zopf has followed out the life-history of this 

 ascomycetons fungus, especially in the instance of C. Jcunzeanum. 

 The ascospores germinate readily in saccharine vegetable juices, 

 solution of sugar, decoction of dung, urine, and even in water. In 

 addition to the mycelium formed in the substratum, there is generally 

 an aerial mycelium, often of great luxuriance. The formation of 

 perithecia begins after a few days, commencing in the centre of the 

 mycelium, and advancing centrifugally. They proceed from both the 

 submerged and the aerial mycelium, originating in the form of short 

 erect branches, with dense and strongly refractive contents. The 

 primary hyphae now branch repeatedly, bending and interlacing, and 

 thus producing a dense ball. No differentiation of ascogenous and 

 enveloping hyphte can be detected, as in other Ascomycetes. In the 

 centre of this pseudo-parenchymatous mass of hyphse is formed a 

 hollow, into which the adjoining cells send down tubular septated 

 projections, the " nucleophyses " ; this results in the first and most 

 important differentiation, into the peripheral part or perithecial wall 

 and the central portion or nucleus. The nucleophyses, which corre- 

 spond to the base of the perithecium, now undergo a more energetic 

 development in comparison to the rest, being not only longer, but 

 branching more copiously, forming a pseudo-parenchymatous cushion, 

 on the outermost branches of which, projecting into the perithecium, 

 are produced the asci, and, since all the terminal branches are fertile, 

 there are no paraphyses. The hyphfe which clothe the lateral walls 

 of the perithecium, branch but little, and remain sterile, may 

 be termed " periphyses," those that constitute the ascogenous cushion 

 " ascophyses." The wall of the perithecium becomes differentiated into 

 an outer layer composed of narrow brown cells with slightly thickened 

 walls, and an inner layer composed of thin-walled turgid cells. 

 About the time when the asci are being developed, a mouth is formed 



* F. Hoppe-Seyler, ' Ueber die Einwirkung des Saucrstoffs auf Gahrungen,' 

 32 pp., Strassburg, 1881. 



t Nova Acta Acad. Leop.-Carol., xlii. (1881) (7 pis.). See Bot. Centralbl., 

 ix. (1882) p. 2.58. 



