ZOOLOGY AND BOTANY, MICBOSCOPY, ETC. 609 



Marcus Underwood. These are 212 in number ; the first was printed 

 in 1878, and the last in 1907, and 78 of them are concerned with the 

 Pteridophyta. It was during the last ten years of his life that Under- 

 wood gave his attention more particularly to ferns, collecting material 

 in the United States and West Indies, and paying several visits to 

 Europe in order to study type-specimens of American species. 



W. N. Olute* publishes obituary notices of Benjamin Davis Gilbert, 

 Lucien Marcus Underwood, and George Edward Davenport, leading 

 students of ferns, deceased during 1907. 



Anatomy and Morphology of Tmesipteris.f — M. G. Sykes describes 

 the external features and the anatomy of Tinesijrteris, based upon material 

 obtained from New Zealand, and shows that there is an endodermis 

 surrounding the single stele in the rhizome, and that it has characteristic 

 markings on its radial walls. The endodermis loses these markings and 

 becomes less obvious at the transition region ; and in the aerial stem it 

 can no longer be distinguished. The pith arises in the centre of the 

 stele in the transition region, and quickly expands to form a large tissue 

 in the stem ; the protostele passes into a medullated monostele without 

 the intermediate stage of solenostele. Growth from a single apical cell 

 occurs in both rhizome and stem. In the fertile branch, as in the 

 sterile, the single bundle entering the axis branches into three, the two 

 lateral traces supplying the leaves. The central bundle supplies the 

 synangium, which occurs at the point of divergence of the two leaves. 

 The single trace entering the synangium pedicel branches into three ; 

 the two lateral diverge and run round the periphery of the septum. The 

 central trace, described for the first time, is an important argument in 

 favour of the axial theory of the sporophyll in the Psilotales, and is re- 

 garded by the author as representing the vascular supply of the apex of 

 the branch. The author searches for evidence of phylogenetic relation- 

 ship with Sphenophyllum. 



Origin of Roots in Lycopodium.l— E. M. Saxelby gives an account 

 <>f the origin of the roots in Lycop odium Selago. They arise near the 

 apex of the stem, but below the first leaves, before the vascular elements 

 have become differentiated ; and they arise from a group of cells : the 

 dermatogen of the root from the innermost layer of the stem periblem, 

 and the periblem and plerome of the root from the plerome of the stem. 

 The root-apex is divided into three meristematic regions, the dermatogen 

 giving rise to the root-cap and epidermis, and the periblem producing 

 four layers of cells over the central plerome. The roots run down 

 through the middle cortex of the stem and emerge from the under side 

 of it beneath the soil ; they do not dichotomise before emerging. Each 

 root is connected with two protoxylem groups of the stem and the 

 inclosed phloem. Leaf-traces, on the other hand, are never connected 

 with more than one set of protoxylem elements. The roots may be 

 diarch or tetrarch, the metaxylem of the former being in two parallel 

 bauds, and that of the latter being in the shape of a horse-shoe. The 



* Fern Bulletin, xv. (1907) pp. 65-70. 



t Ann. of Bot., xxii. (1908) pp. 63-89 (2 pis. and figs.). 



% Tom. cit., pp. 21-33 (1 pi.). 



Oct. 21st, 1908 2 s 



