228 SUMMARY OF CURRENT RESEARCHES RELATING TO 



and of the hyponasty which belongs also to the apex of the sterile 

 shoots, and which does not afterwards disappear, but becomes fixed 

 in consequence of the origin of the female receptacle, and of the arrest 

 of growth in length. The genus, therefore, presents no difference 

 from the rest of the acrogynous Jungermannieee in the position of the 

 female recejitacle. 



In Podanthe, Loplwcolea, and Gymnanthe the receptacle, and hence 

 the fertile tube, are terminal. The normal production of lateral shoots 

 ceases in these genera before the formation of the female receptacle. 

 Lindigina presents as a rule the same peculiarities as Gongylanthusj 

 while Marsjqndium more closely resembles in this respect Calypogeia 

 and its allies. The reproductive shoots originate in an intercalary 

 manner on the ventral side. 



Vegetative Reproduction of Sphagnum.*— C. Warnstorf has 

 observed that when tufts of Sphagnum squarrulosum are decapitated by 

 mowing, the stems put out young buds in the neighbourhood of the 

 tufts of branches, each bud possessing a new cone of gi-owth. These 

 buds develope tufts of branches, which for a time derive their nourish- 

 ment from the parent stem, but soon acquire the power of carrying on 

 existence as separate individuals. This property, together with that 

 of indefinite apical growth, give to the turf-mosses an almost unlimited 

 power of development and reproduction, if only they are supplied 

 with sufficient moisture. 



Fungi. 



Action of Light on Fungi.j — Professor Karl Eegel states that 

 Piloholus crystallinus and Mucor mucedo exhibit positive heliotropism 

 in white light, and also in mixed blue and mixed red rays. In one- 

 coloured red light Piloholus also exhibits positive heliotropism. 

 Mixed blue rays produce a much greater heliotropic effect on both 

 species than mixed red rays. Neither the intensity of the light nor 

 the temperature exercises any influence on the kind of heliotropism. 

 "While sunlight promotes the development of spores and rapid growth, 

 darkness arrests both. The strongly refrangible are more favourable 

 than the less refrangible rays for both these processes. The hyphae 

 grow more rapidly in length in white light than in darkness ; the less 

 refrangible rays are more favourable to this process than the moi*e 

 refrangible. The formation of sporangia and of spores takes place 

 perfectly normally in Piloholus both in white and in mixed blue and 

 red light, and also in darkness ; but most rapidly in white light, next 

 in blue, next in red, and most slowly in darkness. 



Chemical Nature of the Cell-wall in Fungi.t— It is well known 

 that the substance of which the cell-membrane in Fungi is composed 

 does not display the ordinary reactions of cellulose ; and it has hence 

 been described as a peculiar substance, under the name " Fungus- 

 cellulose." Karl Richter has determined that this view is incorrect, 



* Bot. Centralbl., viii. (1881) pp. 219-20. 



t St. Petersbuiger Naturf. Gesellsch., 1881 (Russian). See But. Centralbl., 

 viii. (1881) p. 131. 



X SB. K. Akad. Wiss. Wien, Ixxxiii. (1881). 



