370 Mr. C. C. Babington on the British species 0/ Arctium. 



is desirable to direct attention to the points upon which it seems 

 probable that stress may be best laid. (1.) The arrangement 

 of the heads presents an easy mode of separating two of the 

 species from the others. This character must be used cautiously, 

 for it is only the top of the central stem of the plant that is to 

 be trusted : it and the branches often have the heads arranged 

 in the same manner, but frequently the central stem bears a 

 corymb and the branches racemes of heads. (2.) The form of 

 the heads is of much value, and their size must not be neglected. 

 (3.) Although the shape of the phyllaries is nearly the same in 

 all the plants, their direction is a little different and the appear- 

 ance of the heads is thereby changed. The inner row has not 

 this uniformity of shape, but differs considerably in the several 

 plants. These inuer phyllaries are always bordered by a broadish 

 membrane which sometimes increases in width towards the top, 

 but in other cases narrows gradually to a rigid point. (4.) The 

 florets consist of two parts, the upper of which is tubular nearly 

 throughout. That part which is below the commencement of 

 the free filaments is slender in all the species ; the upper part is 

 always much thicker, varies considerably in form, and its length 

 bears different proportions to that of the lower part. (5.) The 

 phyllaries either fall short of the florets or equal them. In 

 the latter case the corolla alone is to be taken into account, for 

 the anthers and styles are always much protruded. 



It is proper to state here the reasons which have led me to 

 retain the name of Arctium for this genus instead of following 

 DeCandolle in employing it for the A. lanuginosum (Latn.). 

 Linnaeus in his first work (Syst. Nat. published in 1731) gave 

 the name of Arctium to the plant called Lappa by Tournefort, 

 and characterized it as early as the year 1737 (Gen. PI.). In 

 1778 Lamarck transferred the name, under the form of Arction, 

 to his A. lanuginosum without paying the least attention to its 

 previous use by Linnaeus, and applied the term Lappa to the 

 Linnsean genus. It is doubtless true that the ante-Linnsean 

 botanists did use Lappa as a generic name, but it has been well 

 remarked by the Committee of the ' British Association for the 

 Advancement of Science ' appointed to consider the nomen- 

 clature of zoology, that "Linnaeus was the first to attach a 

 definite value to genera, and to give them a systematic character 

 by means of exact definitions ; and therefore, although the names 

 used by previous authors may often be applied with propriety to 

 modern genera, yet in such cases they acquire a new meaning 

 and should be quoted on the authority of the first person who 

 used them in this secondary sense " (Report Brit, Assoc. Man- 

 chester, 1842, p. 110). Applying this excellent rule, which is 

 just as true in botany as in zoology, to the present case, we find 



