ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 319 



ferns which he has examined, showing; whether they have the marginal 

 •or the extra-marginal type of pinna-supply. In the extra-marfjinal type 

 the portion of the pinna-trace which comes from the adaxial side of the 

 leaf-trace is nipped off from the back of a " hook," technically from the 

 abaxial face of the curved leaf-trace ; tlie extreme tip of the adaxial 

 portion of the leaf -trace is continued upward as part of the leaf -trace. 

 In the marginal type, the adaxial portion of the leaf-trace (nearest 

 to the pinna) is itself given off to supply the piima. In both types 

 (usually in connexion with large pinnte) a portion of the pinna-trace may 

 be derived from the abaxial side of the leaf -trace. In the tabular 

 ■scheme of ferns appended to the paper, it will be found that 94 

 ■species (46 genera) possess the extra-marginal type, and 126 species (.51 

 •genera) possess the marginal type. In 7 genera only do both types of 

 pinna-supply occur among the species. In studying the ferns for this 

 'Criterion it is necessary to examine the lower pinnae of the older leaves. 



A. G. 

 Bryophyta. 



(By A. Gepp.) 



Structure of the Cytoplasm in the Cells of Alicularia scalaris. 

 — M. F. RiVETT {Annals of Botany, 11)18, 32, 208-214, pi. and figs.). 

 The author describes the structure of the cytoplasm of this hepatic with 

 special reference to the oil-bodies, their meaning and origin. The oil is 

 a catabolic waste-product and is secreted into vacuoles. Further, as to 

 the cytoplasmic structure of the leaf -cells, the author finds that (1) the 

 actively dividing cells of the growing point and young leaf-bases, where 

 the protoplasm fills the whole cell, show achondriome structure ; (2) the 

 maturing cells have a vacuolar protoplasm forming a spongy network ; 

 (3) in the fully-grown cells the lining layer is so reduced that it serves 

 merely as a covering to its own products. A. G. 



Le Reboulia Raddi. — Ch. et R. Douin {Rev. Gener. de Botanique, 

 1918, 30, 129-145, .5 figs ). The authors have carefully studied and 

 cultivated the hepatic genus Reboulia, which has generally been supposed 

 to comprise a single polymorphic and cosmopolitan species, and have 

 come to the conclusion that three distinct species occur in France — 

 R. hemispherica (L.) Raddi, R. occidentalis, R. Charrieri, the two latter 

 "being new to science. They discuss in detail the essential characters of 

 the species — the inflorescence, the capitulum (with a critical examination 

 of the terms " lobes " and " rays "), the development of the thallus, the 

 spores. In R. hemispherica the androecia are medial on the thallus ; in 

 :the other two species the androecia become divided and laterally 

 displaced. The spores of R. Charrieri are smaller than those of the 

 ■other two species, and are much less conspicuously winged or crested ; 

 also the plant is reduced in all its organs, and the lobes of the capitulum 

 are but 2-4 (as against 4-8 in the other two species). A. G. 



Ptilidium pulcherrimum.— J. Ross {Essex Naturalist, 1918, 18, 

 187-9). The author records the occurrence of the hepatic Ptilidium 

 pulcherrimum in Epping Forest, and describes the conditions under 

 fwhich it is found, and tbe mosses, etc., with which it is associated. 



A. G. 



