356 NATURAL SCIENCE. May. 



the fruit-axis produces no structural changes save such as are of the 

 most trivial kind ; the general type remains unaltered and continuous. 

 But to plant Calamostachys Binneyana upon the top of a Calamite 

 would be as abnormal as to surmount the stem of an Equisetnm with 

 the strobilus of a Lycopod." 



Thus, nearly twenty years ago, Williamson took up the position 

 that, notwithstanding the close general similarity between this spike 

 and that of Eqiiisdiun, the internal anatomy of the axis was so different 

 from that of the stem of Calamites that its affinities could not be with 

 the latter plant, but were rather with Asterophyllites. At that time he 

 regarded the plant he described as Asterophyllites as a somewhat 

 aberrant member of the Lycopodiaceae (7), so that he virtually placed 

 Calamostachys Binneyana in the same group. 



In subsequent memoirs he has returned again and again to the 

 affinities of the spike, but always with the object of strengthening the 

 position taken up in the above extract. In the ninth memoir (1878) 

 he expresses (8) surprise that Mr. Carruthers should still continue to 

 believe in its Calamitean character, and points out that " both M. 

 Grand' Eury and Dr. Dawson have fallen into the accidental error " 

 of making him " regard the Calamostachys Binneyana as belonging to 

 Calamites,'' whereas he has " most strongly opposed that idea." Two 

 years later (1880) fresh specimens of the spike were described by him 

 (g), with the result that they are said to have "fully confirmed the con- 

 clusions" arrived at in 1874, " that Calamostachys Binneyana had not the 

 slightest relationship with the Calamites, but that it had strong affinities 

 with Asterophyllites and Sphenophyllum." The following year (1881) is 

 remarkable for the discovery of a new form of Calamostachys, which 

 Williamson appears at first to have regarded as identical with Calamo- 

 stachys Binneyana, but which he subsequently named Cal. Casheana, after 

 its discoverer, Mr, W. Cash, of Halifax. After a detailed account of 

 its structure, in which great stress is laid on the fact that it contains 

 two kinds of spores, he says (10) : — 



" It is scarcely necessary to say that this discovery of macro- 

 spores and microspores in Calamostachys Binneyana supplies another 

 link connecting this strobilus with the Lycopodiaceae in the same 

 measure that it separates the fruit from the Equisetaceae. . . . 

 This discovery strengthens my old conviction that the true affinities 

 of this strobilus are with the Lycopodiaceae." 



Finally, in the fourteenth memoir, which appeared in 1888, we 

 have his last pronouncement on the subject, which is as follows (11) : — 



" After a prolonged conflict the conclusions of those who have 

 insisted upon the cryptogamic character alike of Calamites and Calamo- 

 dendron, have met with an extensive, though not universal, acceptance. 

 Meanwhile, both the opposing schools of palaeontologists recognise the 

 importance of discovering the fructification of these plants. Mr. 

 Carruthers believed that he had found it in examples of Calamostachys 

 Bi'nneyaiia, and Mr. Binney arrived at a similar conclusion. I have 

 always rejected these conclusions because of the conspicuous diffe- 

 rences between the morphology of the Calamitean twig and that of 



