Boijal Microscopical Society. 51 



Liudley and Hutton, Brongniart, Binney, and myself, none have 

 shown the structure of the leaf bases, and their relation to the stem, 

 except that which I figured in my first communication to this 

 Society ; * but in that figure the single leaf was exhibited in one 

 direction only, and not with that completeness which, by the help 

 of Mr, Butterworth's specimens, I am now able to give. 



As, however, the specimen exhibits several difierences in its 

 internal structure from the Lepidodendron stem which I formerly 

 figured, and to which I have referred, I will describe its structure 

 at length. It is most desirable to have as many types of stem 

 structure, and as many varieties of the same type before us, so 

 that when we come to generalize as to their affinities, we may 

 fairly estimate the value of the difierent variations, and intelligently 

 interpret the affinities of these palaeozoic stems to the similar 

 structures in existing allied plants. 



The differences in the structure of this stem are so distinct from 

 those that have been already published, that it would be quite in 

 accordance with the practice hitherto adopted to give to this frag- 

 ment a specific name. But as the species in Le-pidodendron are 

 distinguished by the form and markings on the leaf scars, and as 

 these are at present unknown in this fragment, it is better to leave 

 it in the meantime unnamed, and trust that the continued labours 

 of Mr. Butterworth, or some other investigator, may result in 

 identifying the named form to which this belongs. The practice of 

 recklessly bestowing names on fragments that obviously belong 

 to, but cannot at the time be certainly correlated with known 

 species, which is followed by some students of vegetable palae- 

 ontology, is not only adding innumerable synonymes to the 

 already heavily-burthened pages of systematic works, but is 

 creating a terrible and a thankless labour for every honest and 

 exhaustive worker. It is, no doubt, a short and ready solution 

 of every difficulty to set aside the labours of previous workers, 

 and it is besides rather flattering to one's self to be the creator 

 of a series of names. But what would be thought of such a prac- 

 tice in any other department of Natural History ? Suppose, for 

 instance, it were discovered that we had in this country another 

 Papilio beside the Swallow-tail, and that one entomologist got hold 

 of a hind wing and found that it had two tails, and so full of his 

 important discovery he figures and describes his fragment as P. 

 hicaudaius, Mihi ; another finds a head with the antennae attached, 

 and these are obviously more club-shaped than the known species, 

 and of course it is P. clavatus, Mihi ; the body falls into the hands 

 of a third, and it is thick and short and blunt, and easily distin- 

 guished from Machaon, so it becomes P. truncatus, Mihi ; the fore 

 wing turns up, and it has got blue lines and spots, and it would be 

 * 'Mon. Micr. Joum.,' vol. ii., PI. XXVII., Fig. 1^. 



