L. Cockayne. — Notes on New Zealand Floristic Botany. 161 



Art. XVII. — Notes on New Zealand Floristic Botany, including Descrip- 

 tions of New Species, &c. (No. 3). 



By L. Cockayne, Ph.D., F.L.S., F.R.S., Hutton and Hector Memorial 



Medallist. 



[Rear! before the Wellington Philosophical Society, 24th October. 1917 ; received by Editors, 

 31st December, 1917 ; issued separately, 30th May, 1918.] 



Plates IX, X. 



I. Introduction. 



In this series of papers, two of which have already appeared,* I am carrying 

 out, as far as lies in my power, the views regarding species and taxonomic 

 procedure expressed in my paper entitled " A Consideration of the Terms 

 ' Species ' and * Variety ' as used in Botany, with Special Reference to the 

 Flora of New Zealand. "f These views are by no means of my own formu- 

 lating. On the contrary, they represent what I believe to be the consensus 

 of opinion of those engaged in the only true way of studying specific distinct- 

 ness — i.e., by means of experiments in genetics according to present-day 

 methods. If my views possess any originality it lies in the method of stating 

 the case and in the proposals suggested for meeting the practical difficulty 

 of making a flora serve its primary purpose of enabling any plant to be 

 readily recognized and accorded its proper name. As the length of the 

 paper cited above and the method of presentation of its arguments may 

 serve to somewhat becloud the practical application of the theories advocated 

 therein, I now briefly state the principles which in this series of papers are 

 the guide for the establishing of species or varieties : — 



(1.) The starting-point in the setting-up of species is the individual. 

 (2.) Groups of individuals which resemble one another in every character 

 and reproduce their like, subject, of course, to unfixed fluctuat- 

 ing variations, constitute specific units and may be designated 

 " microspecies. "J 

 (3.) One microspecies, if all its related microspecies have been oblite- 

 rated or have never existed, constitutes an invariable or fixed 

 systematic species. Examples : Agathis australis, Veronica cu- 

 pressoides, Epilobium pallidiflorum.§ 

 (4.) Two or more closely related microspecies may be united into a 

 group for the sake of : (a) convenience in identification, (b) em- 

 phasizing the close relationship of minor groups (microspecies), 

 (c) phytogeography. 

 (5.) Such a major group as constituted in (4) forms an aggregate or 



collective species. 

 (6.) Aggregate species are the " variable species " of floras. Examples : 



Poa anceps, Ranunculus lappaceus, Pimelea prostrata. 

 (7.) An aggregate species has obviously no real existence ; it is a con- 

 venient abstraction only. 



* Trans. N.Z. Inst., vol. 48, pp. 193-202, 1916 ; and ibid., vol. 49, pp. 56-65, 1917. 



t Trans. N.Z. Inst., vol. 49, pp. 66-79. 



% Other names given to such groups are " biotypes," " petites especes," and 

 " elementary species." 



§ It might well be argued that there are no species which consist of only one micro- 

 species, and that intense study and experiment will demonstrate their polymorphy. 



6— Trans. 



