486 RECOED OF CURRENT RESEARCHES RELATING TO 



is occupied by a cellular procambium enclosed within a pericam- 

 bium or special cellular sheath. From this sheath, at points located 

 at measured distances and in varying numbers, several, hut never 

 less than two, bundles of vessels are developed ; but at the free ends 

 of the peripheral portions of the roots, in the case of Lycopodium, 

 and throughout the entire length in Selaginella, only one such pro- 

 cambial bundle makes its appearance. When perfected, this bundle 

 exhibits a triangular form in the transverse section, the apex of the 

 triangle, which always remains adherent to the pericambium, being 

 occupied by the small and first formed vessels, whilst its broad base, 

 composed of larger vessels, projects into the centre of the pericambium. 

 These conditions reappear in the most exact manner in the rootlets 

 of the Stigmaria ficoides, now universally admitted to be the roots of 

 Sigillaria, as well as of Lepidodendron. 



This and numerous other facts Professor Williamson holds to be 

 conclusive of at least the ordinal unity of the Lepidodendra and the 

 Sigillarice, and of the Cryptogamic character of both. 



Muscineae. 



Comparative Anatomy of Marchantiaceae.* — K." Goebel is able, 

 from his examination of two of the most common native species of 

 Marchantiaceae, to establish a higher development of tissue than has 

 hitherto been supposed to exist in Thallophytes. 



In Fegatella conica the central region of the thallus possesses a 

 number of continuous mucilage-passages ; in a not specially vigorous 

 specimen as many as ten were counted. 



Preissia commuiata also has isolated mucilage-cells, and in addition, 

 a skeleton of isolated rudimentary fibrovascular bundles. These latter 

 appear merely to serve for strengthening the thallus, and not to fulfil 

 any other function. 



Structure of Anthocerotese.t — In the most recent part of his work 

 on the HepaticfB, Leitgeb discusses the structure and relationship of 

 the small number of genera which make uj) the group of Anthocerotefe. 

 He considers the nearest affinity of the group to be with the genus 

 Biella of Jungermanniacese (Eicciaceae). The basilar increase of the 

 capsule he regards as equivalent to the growth of the seta of the 

 capsule of Jungermannia. To the three genera, Anthoceros, Dendro- 

 ceros, and Notothylos, he proposes to add a fourth, AntJwcerites, 

 separated from Anthoceros by the absence of stomata in the wall of 

 the capsule, and by having elaters with spiral thickening-band. 



Fungi. 



Parasitic Fungus of the Mulberry 4— A. Bertoloni disputes the 

 conclusion arrived at by Piccone, that the fungus-mycelium so 

 destructive to the mulberry trees in Italy is that of Agariciis melleus. 

 He maintains, on the other hand, that it belongs to Polyporus Mori. 



* ' Arbeit Bot. Inst. Wurzburg,' ii. (1880) p. 529. 



t ' Untersuch. u. d. Lebermoose,' von Dr. H. Leitgeb. 5 Heft, Anthoceroteen. 

 Graz, 1879 ; see ' Bot. Zeit.,' xxxviii. (1880) p. 157. 

 X 'Nuov. Gioru. Bot. Ital.,' xii. (1880) p. 19. 



