8 HlCKLING, Anatomy of Calaniostadiys Binneyana. 



regarded as their traces. A further argument may be 

 derived from the analogy of the quadrangular steles with 

 four bundles. In these cases I have never seen any 

 indication of the bundle being double. Dr. Scott, in the 

 new edition of his " Studies," states that " there are 

 usually six, sometimes eight" bundles (Scott, :08, p. 51, 

 52), but I presume that he merely considers that in the 

 latter case there may be theoretically eight. In his well- 

 known monograph with Prof. Williamson (Williamson 

 and Scott, '94, p. 905), he says, of the quadrangular 

 steles, " There is no reason to suppose, in this case, that 

 more than one bundle was present at each corner." This 

 statement is certainly true of the great majority of cases. 

 Now, where there are four bundles there are always eight 

 sporangiophores. Hence it would be curious if, in cases 

 where the number of sporangiophores is reduced to six, 

 the number of bundles should be increased to six ! 



This last argument is considerably strengthened by 

 the fact that the same cone which has a quadrangular 

 stele with four bundles and eight sporangiophores in its 

 lower part, may have a triangular stele with six sporangio- 

 phores above. Together with the other evidence, this 

 leaves no doubt, in my mind, that the normal number of 

 bundles in triangular steles is three*. 



The discovery that the number of sporangiophores 

 and of bundles in the stele was variable within the 

 individual cone, resulted from the preparation by Mr. 

 Lomax of a fine series of eight sections, giving serial 

 sections of four distinct cones. Three of the four series 

 show this change, the best cone being that marked A, which 



* It appears to me that in any case the expression "partially fused 

 pairs," commonly applied to the bundles, is objectionable, since one feels 

 little doubt that tne change which was taking place in the evolution of these 

 cones was a gradual division of the bundles. The three groups of tracheids 

 are certainly not the result of the fusion in pairs of six primitive groups. 



