648 SUMMARY OF CURRENT RESEARCHES RELATING TO 



attached bo the leaf-base on the parent plant. Stipules are known in the 

 Cycadeae. 5. The dichotomy of the veins and the absence of a midrib 

 in the pinnules indicate a primitive type. The vegetative organs thus 

 do nor afford much help. G. The fertile frond, partly vegetative, partly 

 reproductive, is comparable to that of Osmundacese, Ophioglossacere, and 

 Aneimia. Nothing like Archseopteris is at present known in the Pterido- 

 sperms. 7. The lobed sporophyllule of Archseopteris suggests affinity 

 rather with Sphenophyllum and Ophioglossum than with a Pteridosperm. 

 The sporangium of the great majority of living Pteridophyta is evascular. 

 In the Ophioglossacese and in the extinct Botryopterideas (e.g.Zggopteris) 

 the sporangium is vascular. In this respect Archseopteris is comparable 

 with Ophioglossacere. The microsporangia of a Pteridosperm are also 

 in a sense vascular. 8. The sporangium of Archseopteris is apparently 

 divided by transverse septa into a series of superposed loculi comparable 

 to one half of a small " sporangiferous spike " of an Ophioglossum. No 

 such shape of microsporangium is known in any Pteridosperm : but in 

 living Angiosperms many genera possess pollen-sacs made multilocular 

 by horizontal partitions. 9. Archseopteris is known from several localities 

 in Europe, Asia, North America, and the Arctic regions. In no locality 

 have seed-like bodies been found connected directly or indirectly with 

 the plant. These localities have not, however, been exhaustively searched 

 for Archseopteris, nor since the Pteridospermea? were founded. 10. 

 Archseopteris occurs in the upper Devonian and Culm rocks ; the Pterido- 

 sperms are known well-developed forms from the Culm or Lower Car- 

 boniferous. The ferns are represented in the Carboniferous by the 

 Botryopterideae. The author is inclined to regard Archseopteris as an 

 ancestral form of the Ophioglossaceaj, until further evidence is forth- 

 coming. 



The same author* gives an account of Archseopteris Tschermaki and 

 other species of the genus found in Ireland. 



Distribution of Equisetum maximum. f — A. Verhulst gives an 

 account of the distribution of Equisetum maximum on slopes along the 

 upper margin of the Marl (Marne de Grancourt) just where it is covered 

 by a thin layer of Jurassic Limestone (Calcaire de Longwy), along the 

 Franco-Belgian frontier. It is along this zone that the plant finds 

 exactly that underground store of moisture which it requires ; and there 

 ii grows in abundance, sometimes associated with Sedum purpureum and 

 Sambucus ebulus. And it is useless to search for it in other situations. 



Asplenium Guichardii.j — R. de Litardiere gives a description of a 

 new hybrid, Asplenium Guichardii, the parents of which are A. foresiacum 

 and A. trichomanis, the former being the preponderant element. It is 

 found in the department of Herault, where also grows A. Pagesii, a 

 hybrid of the same parents but with a preponderance of A. trichomanis. 

 This latter hybrid was described by Litardiere last year. He adds some 

 critical notes on the variability of A. foresiacum. 



* Sci. I'roc. Roy. Dublin Soc, xiii. (1911) pp. 137-41 (2 pis.). 

 + Bull. Soc. Roy. Bot. Belg., xlvii. (1911) pp. 285-90 (map). 

 X Bull. Gcogr. Bot., xxi. (1911) pp. 75-7. 



