610 Proceedings. 



petent to decide, and he would probably base his opinion upon points the 

 cumulative force of which, sufficiently plain to himself, he might find it 

 difficult to explain to others. If albinos were sporadically produced in 

 sufficient numbers to find albinos for partners, and never obtained partners 

 of the normal colour of the species, they would probably have a large pro- 

 portion of albinos in their offspring, which would soon form a species that 

 he thought all naturalists would acknowledge as such. 



Mr. T. W. Kirk mentioned having seen a specimen of the nankeen 

 night-heron near tlie mouth of the Pahau Eiver in March last. The bird 

 had been slightly wounded, but managed to escape capture. Sir Walter 

 Buller had exhibited an albino tui. Now, it was well known that birds in 

 New Zealand showed a decided tendency to assume abnormal plumage. 

 Nor was the peculiarity confined to native species. There was in the 

 Museum a black skylark ; he had seen several specimens of goldfinch 

 exhibiting unusual colours ; and early this year he had noted a sparrow 

 having white wing-feathers, black head, and normal-coloured tail, while 

 the whole of the remaining portions were a decided red. This specimen 

 lived with a large flock of ordinary sparrows about a woolshed on the 

 East Coast. Could Sir Walter Bailer suggest any theory to account for 

 these frequent freaks ? Also, could he explain the reason v.hy dimorphic 

 j)hases of plumage were present in some species ? 



Mr. Richardson pointed out that on the Kermadec Islands the mutton- 

 birds were so numerous as to form an article of food for those who were 

 unfortunate enough to live there. 



Sir Vr alter Buller, in reply, said that the only importance he attached 

 to systematic classification was as an aid to memory' in the study of the 

 natural objects themselves. Birds, like other animals, resolved them- 

 selves into natural groups, and could be most conveniently studied in that 

 manner. The discrimination of genera and species was, after all, 

 empiric, and often very arbitrary. Nothing was easier than to raise the 

 qiccestio vexata, What constitutes the difference between a species and a 

 permanent variety ? On no point probably were naturalists so much 

 divided — some carrying their discrimination of forms to an extreme, others 

 erring in an opposite direction. In fact, most systematists might be 

 divided into two classes, "lumpers" and "splitters." The thing was to 

 hit the happy mean. There was much truth in what 2dr. Maskell had 

 said, and no doubt modifications of structure were of the first importance 

 in the discrimination of species ; but, as to nomenclature, it seemed to 

 him that simplicit}^ was the thing above all others to be desired. To adopt 

 the system more or less in use among ornithologists of making sub- 

 species or varieties was to his mind very objectionable, because it had 

 the effect of encumbering the literature with names. For example, 

 Apteryx bullcri, as it was now called, appeared in Dr. Fmsch's list as 

 Apteryx australis, variety inantelli. According to the generally-accepted 

 view among English systematists, the amount of variation necessary to 

 constitute a species was not of much importance, and might be left to 

 individual opinion, so long as it was persistent or constant. For his own 

 part, he was quite indifferent whether the petrel now exhibited, and 

 which he had named CEstrelata affinis, was regarded as a distinct species 

 or a permanent race, so long as the difference of character was recognized. 

 Admitting the distinction, it was merely a question of convenience with 

 systematists whether to call it by a distinctive name, or to designate it 

 " Species A, variety B." Dr. Finsch considered that this and Q^strelata 

 riioUis, of which specimens were on the table for comparison, v/ere varie- 

 ties of one and the same species ; but Mr. Osbert Salvin, our great 

 authority on petrels, had unhesitatingly pronounced them distinct 

 species. They belonged, however, to the same natural group, and were 

 closely allied. Although easily discriminated now, no naturalist of the 

 present day would deny that they had originally sprung from a common 

 parent. This followed of necessity from an acceptance of the theory of 



