306 PHYSIOLOGICAL BOTANY. 



the sporidia in groups of four, in the form of a tetractys, 

 has often been observed since Mohl described it, but their 

 formation has never been traced so accurately from its 

 earliest origin, as by the author. His observations show 

 that the development of sporidia in the capsules of the 

 Mosses, is effected by a frequently repeated formation of 

 cells within cells, which takes place four times in Poly- 

 trichum, three times in Hypnum, but only twice in several 

 other Mosses. It could not be satisfactorily determined 

 whether the separation of the cells was produced by 

 internal walls, or the granular matter; probably both 

 contribute to it ; a wall is formed on the separation of the 

 nucleus. The formation of cells within cells never occurs 

 during the simple course of vegetation, but this is the case 

 where vegetation returns to generation. 



History of the Growth of Mosses and Liverworts. By 

 C. NAGELI. Zeitschrift f. wissenschaft. Bot., pt. 2, 138. 

 The history of the growth of Echinometrium and seve- 

 ral other Liverworts does not admit of an abstract. 



G. METTENIUS, Contribution to the History of the 

 .Development of the Mov cable Spiral Fibres of Char a 

 hispida. Bot. Zeit. 1845, p. 17. " The two antennae 

 which Thuret constantly observed, I have not been able 

 to find/ 5 says the author ; I have seen them, and this 

 entirely alters the matter. 



Identity of the filamentous and mucoid Conferva. By 

 Dr. SCHAFFNER. Flora, 1844, p. 568. Rendered pro- 

 bable, but not proved. These minute objects certainly 

 much resemble each other ; they are Fungi, not Confervse. 



Caulerpa prolifera Ag. By C. NAGELI. Zeitschrift f. 

 wissenschaft. Botanik, pt. i, p. 131. History of the 

 Development of Delesseria Hypoglossum. By the same 

 author. (Ibid. pt. ii, p. 121.) 



