452 Transactions. 



nomenclature capable of such, easy determination, little " more 

 would be wanted than an agreement amongst botanists them- 

 selves as to the mode of procedure. But in cases where 

 the species has been repeatedly shifted from genus to genus, 

 and where botanists with very diverse views have worked more 

 or less independently of each other, and perhaps without taking 

 much trouble to ascertain what was already published, it is a 

 matter of the very greatest difficulty to ascertain the earliest 

 name. For instance, the late Mr. C. B. Clarke informed me 

 that over eighty different names have been applied to the plant 

 now usually known as Scirpus cernuus. 



Another point which has led to much difference of opinion, 

 and has produced many changes of names, is that several 

 botanists working shortly after the times of Linnaeus were not 

 sufficiently careful in characterizing their new genera. In some 

 instances it has been absolutely impossible to identify them ; 

 in others the identification is uncertain, and cannot be relied 

 upon ; while in not a few cases the genera were not recognised 

 until other names had been proposed and passed into general 

 use. In the latter case there has been much doubt as to the 

 propriety of restoring such names, seeing that their adoption 

 must cause great disturbance of nomenclature and great incon- 

 venience to working botanists. The following example will 

 make this clear : — 



Most New Zealand botanists are acquainted with Spergu- 

 laria media, a common plant in coastal districts throughout 

 the Dominion, and equally abundant in many other parts of 

 the world. The genus Spergularia, in which it is usuallv placed, 

 was founded by J. and G. Presl in 1819. In 1820 the' Swedish 

 botanist Fries objected to its retention, on the ground that the 

 genus had not been fully characterized ; and, at his suggestion, 

 Wahlenberg proposed the name of Lepigonum to take its place, 

 our plant thus becoming Lepigonum medium. Shortly after- 

 wards it was discovered that in Adanson's " Families des Plantes " 

 (vol. 2, p. 507), published in 1763, two genera respectively called 

 Buda and Tissa were shortly characterized, which were evi- 

 dently synonymous with Spergidaria. As the descriptions of 

 both genera occur on the same page, neither can claim priority 

 over the other. According to the Candollean laws (article 55), 

 in such cases an author can choose the name which he prefers. 

 Dumortier, writing in 1827, selected Buda, which would make 

 the name of our plant Buda media. But the change did not 

 meet with the approval of the botanists of that time, andProsl's 

 name of Spergularia passed into general use. Sixty years later, 

 when the trend of opinion amongst systematists had become 

 more favourable to the strict enforcement of the rule of priority. 



