•672 Bryophyten. 



material. Great Variation in the shape of the foot was observed. 

 There is no elaterophore, or any grouping of the elaters. but a 

 general distribution of elaters through the capsule. Jongmans, 



Mc Cormick, F. A., A study of Symphyogyna aspera. (The Bo- 

 tan. Gazette. LVIII. p. 401-418. PI. 30-32. 1914.) 



The material was collected in the vicinity of Xalapa and 

 Texolo in Mexico. The writer could examine the thallus and 

 the Sex organs. At the end of the paper the results are briefiy 

 summarized. 



The thallus of 5. aspera has a central Strand of greatly elongated 

 cells which taper at both ends. The walls of these cells have nar- 

 row pores which are spirally arranged. Like the other species of 

 the genus, 5. aspera is dioicous. The plants bearing antheridia 

 are more slender and less freely branched than the plants bearing 

 archegonia. 



The antheridia are scattered over the thickened part of the 

 thallus on the dorsal side. Each antheridium is surrounded by 

 a Scale. 



The archegonia are in groups on the dorsal side of the thallus. 

 Each group is on a padlike extension of the thallus and is sur- 

 rounded by an involucre. 



More than one embryo may be formed in a group, but so far 

 only one has been found to reach maturity. As the embryo elon- 

 gates, the calyptra and päd also elongate and the old archegonia 

 are left in the tip of the calyptra. The young embryo develops by 

 segmentation simiiar to that formed by a dolabrate apical cell. 



The sporogenous tissue is differentiated relatively late in the 

 history of the sporophyte. The cells which are to form elaters may 

 early be distinguished from the cells which are ultimately to give 

 rise to the spore mother cells. The former cells elongate without 

 further division, while the latter cells undergo several divisions. 

 The walls of the sporogenous mass of cells become gelatinized, 

 and the protoplasts are potentially free in the gelatinous substance. 



The spore mother cell attain their lobing by a slow amoeboid 

 change of the protoplast, and in this movement vacuoles seem to 

 play an important part. The examination of the living sporogenous 

 tissue of other Junger rnanniales verifies the occurrence of this 

 phase in them also. 



Spores with two nuclei have been found, though this is not a 

 usual condition. Jongmans. 



Melin, E., Die Sporogenese von Sphagnum squarrosum Pers. 

 Nebst einigen Bemerkungen über das Antheridium 

 von Sphagiiimi acutifoliuni Ehrh. (Svensk Bot. Tidskr. IX. 3, 

 p. 261-293. 1 Taf. und 2 Texifig. 1915.) 



Die Abhandlung umfasst 4 Kap., nämlich 1) Die Sporogenese 

 von Sphagnum squarrosum, 2) Zur Kenntnis der Chromatophoren 

 bei Sphagnum, 3) Einige Bemerkungen über das Antheridium von 

 Sphagnum acutifolium, 4) Zur Kenntnis der systematischen Stellung 

 von Sphagnum. 



Die Resultate betreffs der Tetradenteilung sind im kurzen wie 

 folgt. Die Sporenmutterzellen, die während ihrer ganzen Entwick- 

 lung sphärisch sind, enthalten in der späteren Proph*ase vier grosse 



