Manchester Alenunrs, Vol. Ivii. (191 3), No. 10- 



XVI. The Root apex and Young Root oi Lyginodendroju 

 By F. E. Weiss, D.Sc, F.L.S. 



{President of the Society.) 

 {Read Novevibir 26th, rgr^. Received for publication September gth, igij.) 



The great interest which has centred round Lygino- 

 deiidron, the fronds of which are so conspicuous an 

 element of the plant remains of our Coal Measures, is 

 due to the giadual recognition that, far from being an 

 ordinary Fern, it and its allies occupied in many respects 

 an intermediate position between the Ferns and the 

 Flowering plants. The first points of resemblance to 

 the lowest groups of the latter, the Cycads, were dis- 

 covered by Williamson and Scott, who investigated 

 their vascular anatomy. They were considered to be of 

 sufficient importance to warrant the separation oi Lygino- 

 deiidron from the Filices and the placing of this plant 

 and the nearly allied Heterangium in a new group, the 

 name of which, Cycadofilices, indicated the intermediate 

 position of the plants as a link between Cycads and 

 Filices. Since the discovery by Oliver and Scott that 

 Lyginodeiidron bore like the Cycads true seeds, the term 

 Pteridospermae has appropriately superseded that of 

 Cycadofilices as the name of the group which is now 

 known to have included a much larger number of fern- 

 like plants of our Coal Measures than was at first thought 

 to be the case. For this reason the term Pteridospermae 

 is, on the whole, preferable to that of Cycadofilices, for it 

 may well turn out that some of the seed-bearing ferns 

 had little direct affinity with the Cycads. As I have 



November 2gt/i, ipij. 



