irresistibly to the view that “botanists who waste their time over priority are like boys who, when sent on an errand, spend their time in playing by the roadside[161].” [Sidenote: TERMINOLOGY AND CONVENIENCE.] There is another point which cannot be satisfactorily settled in all cases by a rigid adherence to an arbitrary rule. How far should we regard a generic name in the sense of a mere mark or sign to denote a particular plant, or to what extent may we accept the literal meaning of the generic term as an index of the affinity or character of the plant? If we consider the etymology of many generic names, we soon find that they are entirely inappropriate as aids in recognizing the true taxonomic position of the plants to which they are applied. The generic name _Calamites_ was first suggested by the supposed resemblance of this Palaeozoic plant to recent reeds. If considered etymologically, it is merely a record of a past mistake, but it would be absurd to discard such a well-known name on the grounds that the genus is a Vascular Cryptogam and far removed from reeds. On the other hand, there often arise cases which present a real difficulty. The following example conveniently illustrates two distinct points of view as regards generic nomenclature. In 1875 Saporta described and figured a fragment of a fossil plant from the Jurassic beds of France as _Cycadorachis armata_[162]; the name being chosen in the belief that the specimen was part of a cycadean petiole, and there were good grounds for such a view. A few years ago Mr Rufford discovered more perfect specimens, in the Wealden rocks of Sussex, clearly belonging to Saporta’s genus, and these afforded definite evidence that Saporta had been deceived by the imperfection of the specimens as to their true botanical position. Owing to the obviously misleading name first given to this plant, I ventured to substitute _Withamia_[163] for _Cycadorachis_, and chose such a term in preference to one denoting affinity, on account of the difficulty of placing the plant in a definite class or family. On the other hand, it has been objected that the original name, despite its meaningless meaning—if the expression may be used—should be retained. A friendly critic[164], in writing of the proposed change of _Cycadorachis_, urges the importance of adhering to the name which was first applied to a genus. The same author pertinently remarks that we can no more dispense with a nomenclature than we can dispense with language. We may extend the comparison and point out that in language, as in scientific nomenclature, conciseness, clearness and convenience should be kept in view as guiding principles. The student must judge for himself what course to follow in each case. While adhering as far as possible to a consistent plan, he must take care that he does not allow his own judgment to be completely over-ridden by a blind obedience to fixed rules, which if pressed too far may defeat their own ends.