1893. THE FRUIT-SPIKE OF CALAMITES. 357 



the axis of the Calamostachys. These differences appeared to me too 

 great to make it possible for the one ever to have been a prolongation 

 of the other." 



Thus up to his latest utterances on the subject Williamson 

 refused to recognise Calamostachys Binneyana as the fruit of Calaiintes, 

 and justly insisted upon the difference between the anatomy of its 

 axis and that of the stem of Catamites as being strong evidence against 

 such a view. He even went further than this. So far back as 1874 

 he maintained (12) "that the only British strobilus of which the 

 internal organisation has hitherto been described, that has any claims 

 to be regarded as the fruit of Calatnites," is that which he figured 

 and described in the Transactions of the Literary and Philosophical 

 Society of Manchester in 1869. Substantially the same statement is 

 made in the memoir of 1888 already referred to, so that on both 

 positive and negative grounds he refused to recognise any connection 

 between Calamostachys Binneyana and Catamites. 



Such was the state of opinion among palaeobotanists when the 

 new and much better-preserved specimens already referred to came 

 into the writer's hands. Looked at from the botanist's point of view, 

 it is obvious that the divergence of opinion is based upon the fact 

 that there is a sort of inconsistency, if the expression may be allowed, 

 between the external characters of the spike and the internal anatomy 

 as hitherto understood. As already pointed out, the former have so 

 close a resemblance to those of an Equisetnm spike, that one naturally 

 looks for the parent plant of Calamostachys Binneyana among those fossil 

 forms most nearly allied to Equisetnm, and by a short step we come to 

 Catamites ; but, on the other hand, the internal anatomy as described 

 by Carruthers, Binney, and Williamson, is so irreconcilable with the 

 anatomy of the stem of Catamites as to justify much that the last 

 authority has written in opposing the Calamitean affinities of the 

 spike. 



An examination of the new material gave what the writer thinks 

 is a complete solution of the difficulty thus presented, and at the 

 same time indicated in what direction to look for the reconciliation of 

 these diverse opinions. 



In the first place, it soon became evident that the centre of the 

 axis of Calamostacliys Binneyana was not vascular, as had so frequently 

 been stated, but was composed of cellular tissue which constituted a 

 true pith. In 1891, when drawing up the first part of an Index to 

 his Memoirs, W^illiamson introduced a brief footnote (13) in connection 

 with Calamostachys Binneyana, which shows that he was beginning to 

 have doubts on this point, and he admits that in the specimens 

 described in 1874 "the elongated medullary cells" were "mistaken 

 for tracheids." He says nothing, however, as to whether this 

 parenchyma is a true pith, such as we find in Catamites, or merely a 

 central parenchyma like that found in the stele or vascular cylinder 

 of some Lepidodendva. On this point, however, the sections referred 



