598 EECORD OF CURRENT RESEARCHES RELATING TO 



leaf-slieatbs liaviiig only three teeth. A. Tomascbek lias succeeded 

 in keeping these first shoots alive for a space of two years. The colls 

 of these shoots possess an active power of vegetative reproduction, 

 and the writer believes that, in favourable circumstances, sporangia 

 may arise on them. The secondary stems produced from them have 

 also leaf-sheaths with only three teeth. 



Muscineae. 



Origin of Tubes in the Nostoc-colonies in Blasia.* — The forma- 

 tion of colonies of Nostoc in the thallus of Blasia, especially in its 

 tballoid appendages or " auricles," has been fully described by 

 Janczewski, Leitgeb, and others. They have also sj^oken of the 

 production of long tubes penetrating these colonies, a phenomenon 

 which has received further elucidation from M. Waldner. The fol- 

 lowing are the main results arrived at : — 



1. The formation of tubes in the auricle of Blasia, when infected 

 by Nostoc, proceeds from the papilla (trichome) which projects into 

 the cavity of the auricle ; this j^apilla consisting of a bluntly conical 

 basal cell and a capitate terminal cell. 



2. The tubes developed from this papilla, in consequence of the 

 infection by Nostoc, are not constituted of a single cell. 



3. In most cases the tube is developed from the basal cell, while 

 the terminal cell remains unchanged and then dies otf, or less often 

 also developes into a tube. 



4. The formation of the tube commences by the upper margin 

 of the basal cell swelling out on one side into the form of a cushion, 

 or putting out protuberances on all sides, which become separated 

 by septa from the parent-cell, grow at their apex, and branch, the 

 lateral branches also becoming separated by septa. 



5. No regularity can be observed in the development of the tubes. 

 The numerous modifications in their origin, number, and branching, 

 are dependent on the development of the Nostoc. 



Fungi. 



Endophytic Fungi in Pollen-grains.f — A. Tomascbek has inves- 

 tigated the occurrence of parasitic fungi within pollen-grains, espe- 

 cially in the largest or " antheridial " cell of the multicellular grains 

 of some Coniferfe. 



Among the pollen of Finns sylvestris were found cells from 

 which zoospores were occasionally seen to escape, and which were 

 identified by Cohn as being closely allied to the Chytridimn pol- 

 linis pini of A. Braun. Tlie writer, however, prefers to establish 

 it as a distinct genus under the name Diplochytrium, distinguished 

 from Chytriditim by possessing a double cell- wall, and also by not 

 being actually endophytic within the pollen-cells. The organism 

 may, however, be simply the resting-stage of a Chytridiiim. The 

 Chytridimn pollinis pini is readily detected within the largest pollen- 



* ' 813. Akiul. \Vi.,s. AVicu,' Ixsviii. (1878) p. 204. t Hji-l., p. Ut7. 



