ZOOLOGY AND BOTANY. MICROSCOPY. ETC. 445 



course delivered by him recently at University College, London. The 

 subject matter is mainly the gross anatomy of the ferns proper, the 

 forms and relationships of their vascular strands. The author, being 

 dissatisfied with the orthodox view that the leaf-trace is the vascular 

 supply of an originally appendicular organ, differing ah initio from the 

 axis on which it is borne, adopts the rival hypothesis favoured by 

 Potonie, Hallier, and Lignier, that the fern-leaf is in phylogenetic origin 

 a branch, or rather a branch-system, of a primitive undifferentiated 

 sporangium-bearing thallus. In the first lecture the origin of the 

 Pteridophyta is considered, and the conclusion is reached that the sporo- 

 gonium of the Bryophyta is not homologous with the sporophyte of the 

 Pteridophyta, but the spores of both are homologous with zoospores of 

 alga3 ; that the common ancestor was an alga possessing both archegonia 

 and zoosporangia, and possessing a temporary alternation of generations. 

 The primitive megaphylly of the Pteridophyta and the leaf -reduction in 

 the Equisetales and Lycopods are discussed. The second lecture treats 

 of the Botryopteridea3, a group of fossil primitive ferns possessing a 

 great variety of vascular system. 



Morphology of the Sporophyll in Ophioglossacese.* — D. H. 



Campbell, having collected in the East Indies abundant material of 

 several species of Ophioglossum, of a species of Botrychium, and of 

 the monotypic Hehninthostachys, has studied the question of the mor- 

 phologic nature of the sporophyll in this group of genera. His conclu- 

 sions are that it is evident that the bundles which supply the spike are 

 not secondarily given off from the main bundles of the petiole, but are 

 themselves the adaxial (inner) bundles which can be traced from the base 

 of the petiole into the spike. This would indicate that the spike is not 

 a secondary development upon the leaf, but is a primary portion of it ; 

 and from a study of the early stages of the young sporophyll it is clear 

 that the spike is really a terminal structure. In the embryo of 

 0. molmcanmn and 0. pedunculosum the young sporophyte develops at 

 first only a leaf and root, the definitive sporophyte arising later as an 

 endogenous bud from the primary root. The first leaf must be con- 

 sidered a strictly terminal organ. The author was fortunate enough to 

 obtain near Buitenzorg specimens of the rare 0. intermedium Hook., the 

 original locality of which in Borneo is lost, and shows that it is not to 

 be confused with 0. pendulum. 



Macrosporangia of Selaginella spinulosa.f — M. Kantschieder 

 publishes a contribution to the history of the development of the 

 macrosporangia of Selaginella spinulosa, founded on material from Tyrol 

 and Styria. The sporangium is a product of the vegetative cone, and 

 arises from a single superficial cell of it. The spore-producing tissue arises 

 not only from the archesporium, but also from cells derived from the 

 sporangia! stalk ; the tapetum is also derived from stalk-cells, and is 

 tardy in development. The sterile cells do not become disorganised at 

 once after the tetrad division of the spore-mother- cell, but gradually 

 disappear as the spores mature. Only four spores are formed in a 



* Amer. Naturalist, xli. (1907) pp. 139-59 (figs.). 



t Jahresb. Niederosterr. Landes Real- u. Ober-Gymn. in Horn., xxxiv. (1906) 

 pp. 1-15 (figs.). 



