876 SUMMARY OF CURRENT RESEARCHES RELATING TO 



and that the structure which approaches most nearly to that of the 

 fertile peduncle of PhyUoglossum is that of Lycopodium Jutieri. 



Under the name of the " organ of Mettcnius " Bertrand describes 

 a small bilobed or furrowed emergence on the lower part of the fertile 

 peduncle immediately below the insertion of the pedicel of the new 

 tubercle. 



The pedicel of the new tubercle has a nearly circular transverse 

 section, and possesses a flattened elliptical central vascular bundle, 

 surrounded by a very thick layer of primary fundamental tissue. In 

 this tissue, at an equal distance from the vascular bundle and from the 

 posterior surface of the organ, is a group of small cells which repre- 

 sent the epidermal cells of Braun's canal. Near the surface is an 

 epidermal layer of cells characterized by thickenings of their radial 

 walls. 



The roots of PhyUoglossum are of endogenous origin ; their single 

 vascular bundle is bicentral and axial ; they do not branch ; they are 

 very unequal in size, and vary greatly in number. 



Muscineas. 



Physiological Function of the Central Bundle in the Stem of 

 Mosses.* — G. Haberlandt shows that the central bundle of the stem 

 of mosses, generally described as a rudimentary vascular bundle, is in 

 fact a water-conducting hadrome-bundle. Mnium undulatum has a 

 sharply defined central bundle with thin longitudinal walls which 

 ultimately become yellowish-brown, and very thin oblique septa. 

 When mature they contain nothing but a watery fluid without starch- 

 grains, oil, or protoplasm. If a freshly cut unmoistened stem is im- 

 mersed to the length of 1-2 mm. of its leafless lower end in an 

 aqueous solution of eosin, the pigment rises only in the central 

 bundle, and there with considerable rapidity. If a freshly cut stem 

 is allowed to transpire for from ten to fifteen minutes without access 

 of water, the cells become for the most part filled with air. 



In Polytrichum this central bundle has a complicated structure ; the 

 longitudinal walls are thick and yellowish brown, the septa thin. It 

 serves also here for the conduction of water, while the tissue which 

 surrounds it, enveloped in a thin-walled dark brown sheath, contains 

 protoplasm, starch, and oil, and represents a rudimentary leptome. 

 This leptome-envelope is evidently a product of the difierentiation of 

 the cortex, which is the ordinary conducting tissue for the carbohy- 

 drates and albuminoids in the typical moss-stem. 



Fungi. 



"Ozonium."! — S. Schulzer (of Muggenburg) describes a new 

 hymenomycetous fungus, Bolbitius Ozonii, the ozonium-like mycelium 

 of which [Ozonium auricomum Link) densely covers the rotten trunks 

 of oak-trees lying on grassy land. It is noteworthy as possessing 

 the "velum universale," absent from other species of £oZfet/eMs, but 



* Ber. Deutsch. Bot. Gesellsch., i. (1883) pp. 263-7. 



t Hedwigia, xxii. (1883) pp. 117-8. Cf. this Journal, ante, p. .5.39. 



