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 Equisetwm 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 Equisetum, 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 Astevophyllites. At that time he 
regarded the plant he described as Astevophyllites as a somewhat 
aberrant member of the Lycopodiacee (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 
(9), 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 Calamutes, but that it had strong affinities 
with Astevophyllites 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 Lycopodiacez in the same 
measure that it separates the fruit from the Equisetacez. .. . 
This discovery strengthens my old conviction that the true affinities 
of this strobilus are with the Lycopodiacez.”’ 
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- 
dendyon, have met with an extensive, though not universal, acceptance. 
Meanwhile, both the opposing schools of paleontologists recognise the 
Importance of discovering the fructification of these plants. Mr. 
Carruthers believed that he had found it in examples of Calamostachys 
Binneyana, 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 
