HIERACIUM AURAXTTACUM L. 289 



colouration of the Fritillaries that the insect is largely invisible 

 when at rest on a flower-head. A similar case is that of the common 

 Orange-Tip butterfly (Anthocharis eardamines) , which regularly 

 alights on the flowers of the Earth-nut (JBunium flexuosum), the 

 chervils (C/icerophi/llum), and allied plants, the colouration of the 

 insect and these flowers being so closely similar as to render the 

 insect difficult to perceive when at rest on a flower. Copper butter- 

 flies also frequented the flowers of the Hieraciitm, and their close 

 similarity of colouring ensured for them equal protection when thus 

 at rest ; but, as they were less numerous, this was, in their case, less 

 noticeable. These various butterflies are, of course, the insects by 

 which the flowers of the plant are mainly pollinated (see Knuth, 

 Plant Pollination, ii. p. (599; 1908). 



As to the Fritillaries, their habit of frequenting the flowers 

 of Hieracium aurantiacum has been recorded, n> doubt, by some 

 Continental observer ; but in this country insect and flower are never 

 found together in abundance, so that the habit has very likely passed 

 unnoticed. Yet three weeks or so later than the date named (when 

 the flowers of the Hieracium were largely over), I saw Fritillaries 

 busy visiting quite a number of different species of flower. 



PLANT NOMENCLATURE : MORE SUGGESTIONS. 



I have read with interest the suggestions in regard to plant 

 nomenclature by Mr. Sprague (pp. 153-160), and agree with most 

 of his proposed changes in tbe International Rules. There can be 

 no doubt that the International Rules could be improved by changes 

 in several of its articles, and if this would lead to a more or less close 

 agreement between the followers of the International Rules and those 

 of other codes, particularly of the Philadelphia or American Code, it 

 would indeed be a goal worthy to work for and would be of great 

 bene tit to taxonomic botany. 



In regard to suggestion No. 1 of Mr. Sprague, I am in perfect 

 accord with him in his desire to revoke Article 36 and to make it a 

 recommendation, as I have already proposed in an earlier article 

 (Journ. Arnold Arb. i. 44-51 [1919]). I also agree with his sugges- 

 tions Nos. 2, 4, 5, and 7, which are excellent, but with No. 3 we 

 begin to tread on difficult ground, as it does not seem easy to decide 

 where to stop in advocating changes of geographic names and what 

 to consider extreme cases. The question may be raised whether 

 a name like Acacia sibirica S. Moore in Journ. Linn. Soc. xxxiv. 

 189 (1899) should not be considered a misleading geographical 

 specific name ; the plant is not a native of Siberia but of Australia, 

 and was named after a well called " Siberia Soak " ; and this is 

 unfortunately not the only case of such misleading names. 



In suggestion No. 6 the rejection of all specific homon} T ms is 

 recommended, which means a serious departure from the International 

 Rules. To attain a " fixity of nomenclature" it seems sufficient to 

 allow a name to stand if its earlier homonyms be really non-valid, 



JOURXAL OF Bol'AXY. VOL. 59. [OCTOBER, 1921.] X 



