796 president's address. 



better than is possible in the present state of our knowledge. In 

 connection with this work I have, as hinted already, been for 

 some time collecting seedlings of various Eucalypts, in regard to 

 which I possess, otherwise, full botanical material. 



The genus Eucalyptv.s is given prominence to for obvious 

 reasons, but the amount of variation in other genera may be as 

 great. Where Australian Acacias have been grown for long 

 periods, e.g.^ in the Riviera and California, variation has (in some 

 groups) proceeded to such an extent that it is often impossible in 

 the present state of our knowledge to indicate the species from 

 which they have sprung. Variation is not confined to the 

 phyllodes, but extends to the minute floral organs. 



10. What is a Species'? 



A species is the embodiment of a theory — a working hypothe- 

 sis. It is a standard or rallying point, around which we range 

 the vegetable units. N"o species can be absolutely definite, except 

 as regards the type itself, although in the present state of our 

 knowledge the contrary may appear to hold good in some cases. 

 We strive after a wrong ideal by making the boundaries of a 

 species too rigid; species-names are a convenience of classification, 

 and the process of variation, the natural manufacture of species, 

 is going on everywhere around us. 



Inasmuch as a species is an hypothesis, there will be varying 

 opinions as to the value of any one in particular. A man may 

 be an extremist in two ways : he may be a consolidator or 

 " lumper " of species; this fault of extremism is comparatively 

 rare. Fortunately in the other direction we have few extremists 

 of the type of Swainson,* who must have spent much of his time 

 with his Latin dictionary hunting out adjectives, and finally 

 "exhausted" the supply. 



Swainson's Report is one worth}^ of more than passing notice. 

 He was an F.R.S. and a respected scientific man (a zoologist), and 



* "Further Papers relative to the Discovery of Gold in AustraHa." Pre- 

 sented to (Home) Parliament, December, 1854. Victoria, 24 Nov., 1853 

 (187). Botanical Report by William Swainson, Esq., F.R.S., pp. 98 et ^eq. 



