122 SUMMARY OF CURRENT RESEARCHES RELATING TO 



Fossil Rhizocarps.* — Sir W. Dawson describes tlie organs of fructifi- 

 cation of cryptogams obtained from the Erian (Devonian) formation in 

 Canada and the northern United States. Ho now regards tho organisms 

 previously described as sporangia under the name of Sjjorangites, and jjlaced 

 under Lycopodiacese, as more nearly allied to the Khizocarpese and 

 especially to Salvinia. He prefers for the whole group the name pre- 

 viously suggested by him, Protosalvinia, though it probably includes several 

 genera of Khizocarpean affinities. The detached discs may be regarded as 

 macrospores, and their cellular envelopes as sporocarps. The diagnoses are 

 now given of five species, viz. P. huronensis, hrasiliensis, hilohata, ClarJcei, 

 and punctata. Sir W. Dawson believes the rhizocarpean macrospores to be 

 the cause of the highly bituminous character of the shales which are 

 charged with them, though there are shales which depend for their in- 

 flammable matter on microscopic debris of an entirely diflerent character. 



Muscineee. 



Capsule of Mosses as an Assimilating Organ.f — Herr F. Magdeburg 

 has examined the structure and functions of the loose "air-containing tissue 

 found in the capsule of a large number of mosses between tho outer wall 

 and spore-sac or foot of the columella, the intercellular spaces being 

 esj)ecially developed at the neck and apoj^hysis, where also are the greater 

 number of stomata. That this develoj^meut is not connected with the 

 absorption of moisture is shown by the fact that it is least marked in those 

 mosses which grow in water or in very wot places, such as Climacium, 

 Dicranum palusire, Wiynclwstegium rusciforme, Aulacomnium palustre, &c., 

 while those which grow in dry habitats, as Grimmia pulvinata, Funaria 

 Jiygrometrica, Polytrichum pilifermn, and species of Barhula and Bryum, 

 disj)lay it to a considerable extent. For tho same reason it is obviously 

 not connected with the process of transpiration ; and similar objections 

 apply to its being associated with respiration. 



The author then adduces reasons for connecting the development of this 

 tissue with the process of assimilation ; the chief reasons being the 

 abundance of chlorophyll which it contains, and the presence of a large 

 number of stomata. 



The structure of the capsule of a considerable number of species is 

 described in detail ; and it is pointed out that the form of this organ is 

 chiefly determined by its assimilating character, its complication of struc- 

 ture being in proportion to the development of the latter. In the Cleisto- 

 carpese, Sphagnacete, and Andrc9eacea> the power of assimilation of the 

 capsule is reduced to a minimum ; while in Polytrichum, Bryum, Mnium, 

 and other erect Stegocarpcje it is very considerable. In proportion to the 

 development exhibited by mosses is the independence of the sporogonium. 



This power of assimilation resides to the greatest extent in the spore- 

 sac, next in the innermost layers of the wall of the capsule, and flnally in 

 the characteristic tissue of the apojihysis or neck. 



Muscineae of Central Africa.;}: — Mr. W. Mitten describes the Mosses 

 and Hepaticae collected by the late Bishop Hanuington in Central Africa, 

 and by Mr. H. H. Johnston on Kilimanjaro, including a large number of 

 new species. 



* Bull. Chicago Acad. Sci., i. (188G) pp. 105-18 (1 pi.). 



t Magdeburg, F., ' Die Laubraooskapsel ala Assimulationsorgan,' 32 pp. and 2 pla., 

 Bcrliu, 1886. 



X Joum. Liuu. Soc. Loud. (Bot.)., xxii. (188G) pp. 298-329 (5 pis.). 



