THE BRITISH ASSOCIATION IN AUSTRALIA 27 
arose from forms already existing by loss of 
opening the debate, the writer pointed out that such a view of 
The mutation gives rise to a new inheritable specific character, 
and is the source of the so-called elementary species. But a com- 
terise fluctuatitfg variability, namely, relative size and degree of 
cess of selection of these rather than a sudden mutation. A 
similar remark applies to the cases of seasonable dimorphism in 
alpine meadows described by Wettstein. 
enerally 
especially where the floral organs were affected, as marke 
changes in these would be detrimental. These afford no evidence 
as to the origin of species in Nature. 
