VhXJ^T NOMEXCTATITRE^ A REPLY 138 



In return for these concessions lie would be prepared : — 



4. To recognize as " nomiua conservanda " such antedated current 

 names as have been applied to genera credited with at least 100 

 (or possibly 50) species. 



5, To discuss whether genera undescribed yet accompanied by 

 citation of species should be rejected. 



Let us now estimate the number of name-changes which on this 

 basis would have to be accepted l)y adherents of the International 

 Eules. Among the " nomina conservanda " 41 genera including 

 75S0 species are credited by Dalla Torre and Harms with 100 species 

 or more, and 50 genera comprising 8257 species, are credited with 

 50-90 species each. Assuming that 100 species were taken as the 

 minimum for " nomina conservanda " there wouklbe a gro.ss saving of 

 7580 name-changes. The net saving would be considerably less, as all 

 ** nomina conservanda*' (with at least 100 species) Avhich are valid 

 under the American Code would have to be deducted. Among these 

 are Fimhristijlis^ Rliyncliospora, Eidopliia, BalbophyUum^ JPilea, 

 Oxytropis, Vernonia, Mikania, and probably others. Those mentioned 

 comprise altogether 1560 species, so that the net saving would, at the 

 most, amount to about 6000. Deducting this from the total of 15,000 

 changes entailed by the adoption of the American Code unaltered, 

 we find that the acceptance of Dr. Pennell's suggested compromise 

 would involve about 9,000 name-changes of sjx^cies, if " nomina con- 

 servanda " were restricted to genera credited with at least 100 species 

 by Dalla Torre and Harms. Even if genera credited with at least 50 

 species were included, about 6000 name-changes would be required. 

 The figures speak for themselves. It will be noticed that I have not 

 taken into consideration No. 5, the rejection of typified but undescribed 

 genera, which is not definitely conceded by Dr. Pennell. The number 

 of changes which would be saved were this conceded would, however, 

 be relatively insignificant» 



G-EXERIC HOMONTMS. 



I entirely agree with Dr. Pennell that the monographer of one 

 group of plants should not be required to pursut3 scattered researches 

 on other groups in order to satisfy himself that some early name long 

 considered a synonym is justly and permanently so treated. The 

 validity or non-validity of the early name often depends on the generic 

 concept adopted, and may, therefore, be a matter of opinion. Thus 

 those who consider A7c/^-rm Dum. (1827) a synonym of Linaria will, 

 under International Eules, adopt Kichxia^ l^lwmQ (1828) for the 

 apocynaceous genus afterwards named Kihafalia by G. Don. Those 

 who YQ^-Ai\\Kickxia Dum. and Linaria as separate genera A\ill, on the 

 other hand, call the apocynaceous genus Kihafalia. Thus in this and 

 similar cases the International Rules make the nomenclatural validity 

 of a generic name dependent on the taxonomic validity of a genu's 

 belonging to another family. Instead, however, of treating all generic 

 homonyms as invalid, as Dr. Pennell suggests, the Gordiali knot may 

 be cut just as decisively and more satisfactorily by placing such 

 generic homonyms as are in current use on the list of " nomina con- 

 servanda," and treating the remainder as invalid. 



