III. 

 The Fruit -Spike of Calamites : 



A CHAPTER FROM THE HISTORY OF FOSSIL 

 BOTANY. 



FOR many years there has been much doubt and uncertainty 

 among palaeobotanists as to whether or not the fossil spike 

 now known as Calamostachys Binneyana, Schimp., is entitled to be 

 recognised as the fruit of Calamites. It was so regarded by Carruthers 

 (i) in 1867 and by Schimper (2) in 1869, and Binney (3), who 

 described it in 1868 as the fruit of Calamodendvon commune, was 

 practically of the same opinion, since the plant so named by him is 

 one of the forms of Calamites. Williamson (4), on the other hand, 

 has persistently maintained that its affinities are rather with the 

 Lycopodiaceae, and that the only spike entitled to rank as the fruit of 

 Calamites is the one described by him in 1869, and more fully in 

 1888, and which is very different in many respects from Calamostachys 

 Binneyana. 



Recently the present writer has had an opportunity of studying 

 a fine series of new preparations of the spike, belonging to Mr. W. 

 Cash, of Halifax, and in a paper shortly to appear in the Pro- 

 ceedings of the Yorkshire Geological and Polytechnic Society, he 

 claims to have fully established the fact that it is the spike of some 

 form of Calamites. The time seems opportune, therefore, for a brief 

 historical retrospect of the treatment accorded to Calamostachys 

 Binneyana by those palaeobotanists who have endeavoured to determine 

 its affinities from a study of its structure. 



As described by Carruthers in 1867, Calamostachys Binneyana con- 

 sists of an axis, around which are placed in close array a number of 

 whorled appendages. These appendages are of two kinds, whorls of 

 sterile bracts alternating regularly with whorls of stalked structures 

 carrying sporangia containing spores. The latter have peltate heads, 

 and closely resemble the sporangiophores of Eqnisetiim — so closely, 

 indeed, that were the alternate whorls of sterile bracts suppressed or 

 replaced by structures of the other type, the spike of Calamostachys 

 Binneyana might well be taken for a spike of Equlsetum. 



The specimens at the service of Carruthers appear to have been 

 imperfect and not well preserved, as the minute anatomy of the spike 



