1898] NOTES AND COMMENTS 223 



to descent. Comparison, aided by experiment, supersedes all other 

 methods, and the results which follow raise the question of ter- 

 minology of parts which have arisen by parallel development. In 

 parts which are of secondary importance, such as stipules, pinnae, 

 the indusium, hairs, glands, the inconstancy of their occurrence 

 points to independent origin by parallel development in a high 

 degree ; in parts of greater importance, such as leaves, a parallel 

 development may also be recognised, though in a less high degree ; 

 in the case of sporangia, their acceptance as a category sui generis 

 dispelled the old view of their various origin from vegetative parts; 

 but we must remember that this does not by any means exclude a 

 parallel development also in them, by enlargement and septation 

 from some simpler spore-producing body, though this is not yet a 

 matter of demonstration. There are two extreme courses open to 

 those who wish to convey clearly to others such matters as these : 

 the one 'is to use a separate term for each category of parts, which 

 can be followed as maintaining its individual or essential identity 

 throughout a recognised line of descent — in fact, to make a poly- 

 nomic terminology of members run parallel with a polyphyletic 

 development ; the other course is to make it clear always in the 

 use of terms applied to parts, that they do not contain any evolu- 

 tionary meaning, and to use them only in a descriptive sense. 

 Perhaps the former is the ideal method, and it may be a desirable 

 thing, as polyphyletic origins of parts become more established, that 

 the terminology should be brought to reflect at least the more im- 

 portant conclusions arrived at. For the present, the whole matter 

 as still so tentative that it is well to be content with something 

 which falls short of the ideal, and to maintain the usual terms, such' 

 as stem, leaf, root, hair, sporangium, &c, as simply descriptive of 

 parts which correspond as regards general features of origin, posi- 

 tion, and nature ; but with no reference either, on the one hand, to 

 conformity to any ideal plan, or, on the other, to any community by 

 descent — in fact, we shall preserve the original pre-Darwinian sense 

 of these words, which was purely descriptive, and avoid any attempt 

 to read into them any accessory meaning." 



Fokm and Function 



"And it was full of bones ; . . . and lo, they were very dry." — Ezekiel. 



One of the most serious drawbacks to the study of Botany as it is 

 put before us in recent text-books, especially English text-books, is 

 the dry unlifelikeness of the part devoted to Morphology. And 

 ■especially external morphology, the comparative study of the general 

 form and development of the plant-members, which, completely 

 divorced as it has been from the study of function, reserved for the 

 i-hapter on physiology, has often degenerated into a succession of 



