236 NOTES ON THE TEASELS. 



one plant and the spine of the other, as every transition between 

 them can be found. It would seem that in most cases they are 

 nourished directly from the fibrous vessels, no other tissue inter- 

 vening. For instance, in the serrature of the mid-rib — the most 

 persistent line of prickles in both plants — the epidermis closely invests 

 a bundle of fibres for the whole length of the leaf. It further seems 

 that the vitality of the prickles is dependent on the presence of the 

 growing fibres, and in that respect they may be regarded as secondary 

 appendages. This will perhaps account for their presence on the 

 stem o{ D.pilosus at an early, that is, fast-growing stage. 



No functional importance appears to attach to the prickles. We 

 may, however, safely prognosticate their further development in direct 

 proportion to the increase of the vigorous tissue on which they 

 depend. As we have seen that this tissue is such a capricious and 

 increasing quantity, the plant bids fair to become eventually a spiny 

 monster. 



Any mention of the leaves of D. pilosus would be incomplete 

 without a special reference to the pair of characteristic leaflets, occur- 

 ing as before noticed at the back of the main limb. Do these still 

 exist as relics of an earlier form ? My ignorance of the other 

 members of the genus will not allow me to discuss that question ; 

 but I can certainly say that no such appendages ever occur in 

 D. sylvestris. 



Comparing the two British species, it seems to be correct to say 

 that the one (sylvestris) is vigorous and variable, and tends to depart 

 from forms which may have been ancestral. The other {pilosi/s) is 

 much less vigorous, and shows affinity with forms {Ce/>/ia/aria and 

 Scabious) which also may have been ancestral. 



[At the reading of the above paper. Prof. Boulger communicated 

 the following remarks : — 



" I am sorry that I cannot get down to the meeting, as I should 

 have liked to say a few words on Mr. French's paper on Dipsaci's. As, 

 how'ever, you have kindly given me an opportunity of seeing the 

 paper, I may briefly state what would have been the substance of 

 my remarks. Generally, I may say that I consider that the chief 

 mistake of the modern students of the new teleology — the followers of 

 Mr. Grant Allen, with whom I must class Mr. French — is that they 

 constantly look for some immediate utility to the possessor in every 

 detail of structure. In so doing, they often, I think, overlook two 

 large classes of structures, which I may term ancestral VLnd indifferent 

 respectively. The first class, the ancestral, includes : (i.) the 



