3i 



guide the pollen-grains in the right direction. This has been 

 regarded as a primitive type of seed ; it is certainly a peculiar and 

 indeed unique form. 



The preservation of the Palaeozoic seeds is often surprisingly 

 good ; it is quite a. common thing to find the pollen-grains in the 

 chamber destined for their reception, and in many cases it has been 

 observed that each grain had a many-celled structure. From the 

 analogy of Cycads and the Maidenhair Tree, it is almost certain 

 that these cells of the pollen-grain produced moving sperms ; there 

 is no evidence as yet that a pollen tube was formed, and it may 

 well be that in those early days the spermatozoids had to depend 

 entirely on their own activity to make their way from the pollen- 

 chamber to the egg-cells. 



The Seed-Ferns (or Pteridosperms, as they are technically 

 named) must have formed a group of vast extent in Palaeozoic 

 times. Although the direct proof of connection between seed and 

 plant has only been found as yet in a few cases, yet in a great 

 majority of the fern-like plants all the probabilities point that way* 

 On present evidence we are justified in believing that at least two- 

 thirds of the apparent ferns of the Carboniferous age were in reality 

 seed-bearing plants allied to the Cycads, and if so, this newly 

 discovered class was the most extensive of all known groups of 

 plants in those days. Our still very imperfect knowledge of the 

 Devonian flora indicates that the seed-ferns were already prevalent 

 at that early period. 



The resemblance to ferns which exists to some extent in living 

 Cycads, and to an infinitely greater extent in their Palaeozoic prede- 

 cessors, is far from being fallacious. Besides the mere habit, there 

 is much in the anatomical structure and in the characters of the 

 male fructification to indicate a real affinity with the fern-stock. 

 The connection, however, must lie enormously far back in geological 

 time. 



I have only had time in this address to speak of the Fer?i-like 

 seed-plants of the Coal period. There were other seed-plants, no 

 less ancient and of a higher type of organisation, approaching in 

 some respects our living Coniferae. Their existence at so early a 

 period affords a striking proof of the vast unknown course of 

 evolution which lies behind our oldest palaeontological records of a 

 Land-flora. 



* * • * * 



The address was illustrated by a large number of lantern- 

 slides, mostly from photographs of the specimens. 



