TRANSACTIONS OF SECTION K. 



843 



described from European stems, while the male flowers tear a close resemblance 

 to the fertile fronds of a Marattiaceous fern. We have watched the progress of 

 Mr. Wieland's researches with keen interest and look forward to further important 

 developments. With some of us, indeed, the feelings of the ideal student of 

 science are in danger of being overshadowed by a sensation akin to envy and a 

 desire to invade American territory. 



c. Ginkgoales. 



Before leaving the Gynmosperms a word must be said about another section — 

 the Ginkgoales — represented by the Maidenhair-tree of China and Japan. Ginkgo 

 (or Salisburia) biloba has almost, if not quite, ceased to exist in an absolutely wild 

 state, but as a cultivated tree it has now become familiar both in America and 

 Europe. The living Maidenhair-tree is in truth an anachronism, a solitary rem- 

 nant that brings us into touch with a vanished world and appears as an alien 

 among its modern associates. The abundance of fossil leaves, like those of Qirikyo 

 biloba, and of other slightly different forms referred to the genus Baiera, associated 

 not infrequently with remains of male and female flowers, demonstrates the 

 ubiquitous character of the Ginkgoales during the Rhsetic, Jurassic, and Wealden 

 periods. In the Jurassic shales of the Yorkshire Coast, Ginkgo and Baiera leaves 

 occur in plenty, some of them practically identical with those of the existing 

 species. The abundance of fossil Ginkgoales in other parts of the world — in 

 Australia, South Africa, South America, China, Japan, North America, Green- 

 land, Franz Josefs Land, Siberia, and throughout Europe — demonstrates the former 

 vigour of this class of plants, of which but one member survives. This type of 

 Gymnosperm is distinctly foreshadowed in the Palaeozoic vegetation, and as recently 

 as the Eocene period a species of Ginkgo, indistinguishable in the form of its leaves 

 from the living Maidenhair-tree, flourished in Western Scotland. 



The accompanying table of distribution shows how extensive was the range of 

 the Ginkgoales in the Mesozoic era — both geographically and stratigraphically. 



Geographical Distribution of the GlXKGOALBS. 



d. Ferns, 



Although many of the Mesozoic ferns are preserved only in the form of sterile 

 fronds and are of little botanical interest, several examples of fertile leaves are 

 known which it is possible to compare with modern types. The Polypodiaceae, 



