Morphologie, Teratologie, Befruchtung, Cytologie. 419 



Stephens, E. L., The Structure and Development ofthe 

 Haustorium of Striga lutea, (Ann. Bot. XXVI. 104. p. 1067— 

 1076. 1 pl. Oct. 1912.) 



Striga (N.O. Scrophulariaceae) is a semi.parasitic S. African 

 annual occurring as a root-parasite on grasses and in the maize. 

 The author gives a description of the appearance and habit of the 

 plant, and gives an account of the structure, origin and develop- 

 ment of the haustoria. The transparency of the tissues ofthe mother 

 root allows the haustoria to be readily studied, they are clearly 

 exogenous in origin, shew no homologies with lateral roots and are 

 probabl)^ organs sui generis. 



The mode of nutrition of the parasite is obscure, for thou^h 

 part of the life history is passed Underground as a total parasite, 

 there is no System formed by means of which conduction of assi- 

 milated food can take place; the haustoria are relatively short lived, 

 and there is no storage of food such as occurs in some parasites. 



E. de Fraine. 



Stephens, E. L., Note on the Anatomy of Striga lutea L o w r. 

 (Ann. Bot. XXVL 104. p. 1125—1126. Oct. 1912.) 



The aerial stem in the mature State shews the structure cha- 

 racteristic of the Order Scrophulariaceae, and is almost identical with 

 that of Melanipyrum pratense. The author describes the hairy cove- 

 ring, the leaf, the root, and the transition from the aerial to the 

 subterranean stem. 



The Chief feature of the plant is the comparatively feeble deve- 

 lopment of mechanical tissue, this is correlated with the small size 

 and partially subterranean habit. E. de Fraine. 



Thoday (Sykes), M. G. and E. M. Berridge. The Anatomy 

 and Morphology of the Inflorescences and Flowers 

 of Ephedra. (Ann. Bot. XXVL p. 953—985. 1 pl. 21 textfig. 1912.) 



In this paper the external morphology and vascular System of 

 the inflorescences and flowers of various species of Ephedra are 

 described and illustrated in great detail, and the homologies of the 

 parts in question are fuUy discussed. 



It is found that the method of supply of the axillary fiower 

 buds is similar in essentials to that of the vegetative buds in the 

 axils of the ordinary leaves. The structure of the outer covering of 

 the ovule and its method of vascular supply do not support the view 

 that it represents the first whorl of leaves of an axillary shoot. It 

 is regarded by the authors as an integument. The opening of the 

 micropylar tube is closed in the fertilized ovule by a hardened plug 

 of mucilage, and the chink between the two integuments is closed 

 by papillae which grow out from the epidermis of the outer cove- 

 ring and firmly clasp the inner. 



From the evidence available it is concluded that the structures 

 in the axils of the fertile bracts in the male cone are to be regarded 

 as flowers, or little strobili, each consisting of one axis bearing 

 four leaves. The bi-partite sporangiophore, with its paired bilocular 

 sjT^nangia, is compared with the six-partite disc of sporophylls in 

 Welwitschia and with the multipartite disc in the Bennettitales. 



Whether the female flower in Ephedra and Welwitschia is, like 

 the male, morphologically a little strobilus is not easy to decide, 



