326 SUMMARY OF CURRENT RESEARCHES RELATING TO 



the particular habitat of the parent plant. They differ from those of 

 other species of Radula in that thej are stroncjly developed before 

 becoming detached, putting out several initials, from which the new 

 plants grow. There is a peculiar fusion of the leaf-lobules and of the 

 gemmje-outgrowths. The author also makes remarks on the antheridia, 

 calyptra-formation, and leaf -growth. 



Lepidozia in France.*— C. Douin writes on the French species of 

 the sub-genus Microlepidozia. From Lepidozia setacea have been split 

 off two species — L. trichoclados K. Miill. in 1899, a German plant ; and 

 L. sylvatica Evans in 1 904, an American plant. Both these have now 

 been found in France. Douin describes the microscopic characters of 

 the involucral bracts in which the three species differ from one another, 



Nardia LindmaniLf — V. Schiffner gives a careful description of 

 the morphology and structure of Nardia Lindmanii Steph. founded on 

 a careful examination of the original specimen. He comes to conclusions 

 very different from those published by Stephani,| especially as regards 

 perianth and involucre. Schiffner transfers the species to Notoscyphus, 

 and finds it to be paroicous, and allied to N . liitescens. 



Lepicolea quadrilaciniata.§ — Y. Schiffner describes in detail the 

 Btructure of Lepicolea quadrilaciniata, collected in Patagonia by P. 

 Dusen. The previous descriptions of the plant by Sullivant and Stephani 

 are incomplete. Schiffner transfers it to the genus Blepharostoma. 



Leaf-structure of Polytrichum.||— J. R. Lee publishes some notes 

 on leaf -sections of Polytrichum. He calls attention to the highly' 

 organized development of the gametophyte in this genus, to its 

 specialized conductive system, and its elaborate leaf-structure, the broad 

 midrib bearing on its upper surface a dense series of parallel lamellae 

 which function as the palisade-tissue of the leaf. He describes the 

 cell-structure of these lamellae, showing how the uppermost row of cells 

 differs in character in the different species. And he points out the 

 mechanism employed in the hygroscopic contractions and movements of 

 the leaves. 



Sclerenchyma of Polytrichum.f — W. Lorch writes on a peculiar 

 form of sclerenchymatous cell in the stereomes of Polytrichum commune. 

 He finds a great difference in the form of the lumen of the stereids, 

 particularly in those of the larger dorsal stereome. 



Air-chambers of Riccia.**— W. Pietsch writes on the development 

 of the vegetative thallus of Riccia, and in particular of its air-chambers. 

 He finds that the air-chambers arise schizogenously in previously solid 

 tissue. The development of the air-chambers stands in close connexion 

 with the segmentation of the tissue. This takes place (as Leitgeb recog- 

 nized in the early stages) in this way— that a horseshoe-shaped row of cells 



* Bull. Soc. Bot. France, Session 1910, pp. li-lvii (tab.) 



t Hedwigia, li. (1912) pp. 273-77 (figs.). 



t Bih. Svensk. Vet. Ak. Handl., xxiii. afd. iii. (1897) p. 25. 



§ Hedwigia, li. (1912) pp. 278-82 (figs.). 



II Trans. Nat. Hist. Glasgow, viii. (1911) pp. 186-7. 

 «|| Ber. Deutsch. Bot. GeselL, xxix. (1911) pp. 590-4 (figs.). 

 ** Flora, n.f. iii. (1911) pp. 337-84 (figs.). 



