2 6o SCIENCE PROGRESS. 



only strengthens my old conviction that the true 

 affinities of the strobilus are with the Lycopodiaceae ". Yet 

 a figure in the same memoir shows in the most striking 

 way the resemblance of the peltate scales to those of 

 Equisetum. 



In 1887 the memoir appeared "On the True Fructifica- 

 tion of Catamites" (xiv.). The strobilus described here is 

 the same as that recorded in 1870 (xxiii.), but in the mean- 

 time several fresh specimens had been discovered, and the 

 structure worked out in the most painstaking manner. The 

 importance of this work consists in the fact that a fructifica- 

 tion with axillary sporangiophores {Pal&ostachya of Weiss) 

 was proved to be borne on a peduncle with the exact struc- 

 ture of a Calamitean stem. Williamson regarded this as 

 the only fructification hitherto discovered, which had any 

 claim to be regarded as that of a Calamite. 



In 1 888 (mem. xv.) Williamson recognised for the first 

 time, though in somewhat guarded language, the existence 

 of a pith in the axis of C alamo stachys, and so gave up the 

 one basis for his old position. In the same memoir he 

 gives the finest figure of the peltate scales which has ever 

 been published, and points out that they "approach even 

 more nearly than they were previously known to do, to 

 those of the living Equisetums ". At this time he said 

 nothing more definite as to affinities, but in his Index, part i., 

 1 89 1 (25*) Calamostachys found its proper place at last in 

 the family Calamariese. 



In a paper published at Manchester in 1886 (25), a use- 

 ful and very clear comparative account of the anatomy of 

 the three genera, Catamites, Catamopitys, and Calamoden- 

 drou, is contained. 



The present writer does not think it necessary to make 

 any detailed reference to the later memoir, in which he him- 

 self co-operated (29). A statement of the present position 

 of our knowledge of Catamites will be found in Mr. 

 Seward's article (43). Enough has been said to show in 

 how large a degree this knowledge has been acquired 

 through Williamson's labours. 



The Calamites are a group the affinities of which may 



