206 THE .lOUKNAL OF UOTANY 



THE DISTRIBUTION OF FERNS. 



At the meeting of the Linnean Society on June 1st, Prof. A. C. 

 Seward delivered the third Hooker Lecture, entitled " A Study in 

 Contrasts : The Past and Present Distribution of certain Ferns," 

 illustrated by lantern-slides. 



The lecturer stated that a botanist, especially one whose interest 

 is not limited by the world of to-day, feels a cei-tain kinship with the 

 archaiologist who seeks information on the life and nature of the 

 people who fashioned and used the material discovered in the course 

 of excavation. " For the vegetable kingdom also," as Asa Gray said, 

 '* there is a veritable archaeology." The discovery of a deposit rich in 

 fossil plants throws a light interesting to the systematist or to the 

 student of plant-geography, but our aim is to see in imagination the 

 plants of other days as though they still lived, and the mechanism of 

 the organism and something of the conditions under which it grew. 

 The object of this lecture is to give examples of the application of 

 palseobotanical enquiry to problems of plant- geography ; to follow 

 into the ages which man never knew, the historj^ of some families of 

 Ferns ; to trace their wanderings and to discover their original home. 

 The data gathered from existing j^lants must be supplemented by 

 records of the rocks, records as Darwin said, of a history imperfectly 

 kept, and of this chapter only here and there a few lines. 



Once established. Ferns have a power of spreading by vegetative 

 means, and the lightness and resistant nature of their spores enable 

 them to play a successful role as colonisers and emigrants to new 

 countries. When Treub visited Knikatau three years after its violent 

 volcanic eruption, he found eleven species of Ferns as pioneers of the 

 new Hora. As a class Ferns are cosmopolitan, though certain of 

 them are strictl}^ limited in their range and highly sensitive to 

 the influence of ph3^sical or climatic conditions ; the Bracken, 

 Cysfopteris fragilis and Polystichum Lonchitis were adduced as 

 examples. 



The following families were then passed in review : Gleicheni- 

 acea3, Matonineae, Dipteridinese, Schizsecaceae, and Marattiaceae ; the 

 lecturer's object being to bring together some of the facts already 

 published than to attempt to add much that is new. Palaeozoic forms 

 were excluded, partly because of the difficulty of precise statement on 

 their affinity, but chiefly because it is not until the Mesozoic era that 

 existing types became clearly defined. Twice only had he collected 

 fronds of Gleichenia; on the edge of a Malayan forest where it 

 luxuriated under a tropical climate, and from sediments deposited in 

 a delta or inland lake on the submerged fringe of Cretaceous Green- 

 land. The apparent identity of the living and the dead gives reality 

 to ■ Carpenter's aphorism : " We are still living in the Cretaceous 

 period." In one of his letters, Hooker expresses the opinion that 

 *' Geology gives no evidence of a progression in plants," and adds : 

 *' I do not say that this is a proof of there never having been a 

 progression — that is quite a different matter — but the fact that there 



