208 LEPIDODENDREAE. 



already given. But since something must have had its place there, he pro- 

 ceeds to study living Lycopodiaceae in order to find an analogue for this 

 something that is required. And so the bulbils of Lycopodium Selago and 

 L. lucidulum must be pressed into the service. The marks in Ulodendron 

 are thereupon declared to be the scars of bulbils, of the nature of which 

 the author l distinctly says that he knows nothing. And when he never- 

 theless endeavours to show that these hypothetical bulbils were developed 

 in the axils of leaves by explaining a small irregularity in the arrangement 

 of the leaves, which was observed on a bit of stem 2 , as a young state of the 

 same, the arbitrary character of the assumption is so obvious that it need 

 not be submitted to closer examination. A specimen described by 

 Goldenberg, in which Stur thinks that he has seen the basal portions at 

 least of his bulbils, will be noticed again below, when the genus Lepido- 

 phloios is under consideration. If we try in this way to pick out the 

 course of thought from among the many details of the account, the fallacy 

 which is at the bottom of the whole theory comes out to the light of day. 

 I myself draw only this conclusion from the facts, that there were several 

 forms of Lepidodendron with similar or the same sculpture on branches 

 and stems, which differed however essentially in the position and mode of 

 development of their cones. We have only to compare in reference to this 

 point the living species Lycopodium annotinum and L. laterale from 

 Australia. And since cones of fructification of the most various forms are 

 known in abundance and there are no examples of brood-buds, I take my 

 stand in this matter entirely on the ground of facts. It may be observed 

 here that cases have recently become known, in which cones are still 

 attached to the scars in Ulodendron. Such a case has been described by 

 Thompson 3 , though it would appear from the figure not to be entirely 

 beyond the reach of controversy. There is another specimen about which 

 there can be no doubt, also found by Thompson near Edinburgh but not as 

 it seems yet published, which I saw some years ago when I was with 

 Williamson in Manchester, and which he has noticed incidentally 4 . Here 

 the cones are sessile and form cylinders of considerable thickness. It 

 might therefore be expected that a pressure-surface would be formed 

 between the cones and the stem which probably increased in thickness 

 during their development, and it must have been cup-shaped to fit the 

 base of the cone. The place of separation will then be deeper and more 

 excentric in proportion to the acuteness of the angle which the cone forms 

 with the stern which bears it ; nor can the displacement of the leaf-traces 

 from their normal position in the cup-shaped scars cause any surprise in 

 view of this mutual pressure. 



1 Stur (5), p. 263. 3 Stur (5), p. 370; t. 23, f. 3. 3 Thompson (1). 4 Williamson 



(1), x, p. 499. 



