426 
Mr Gardiner, On the Unit of Classification 
continue to grow. Zoology as a science commenced with the 
doctrine of evolution, a generalisation of facts. Species in the 
older sense are not, but the meaning of the term is clear to all. 
It is not unscientific to call each twig of our tree by a separate 
name. In nature each twig is different from its neighbour, and 
is many times reduplicated. Each replica varies somewhat, but 
the main characters of the twig are repeated in all. New twigs 
may perhaps be formed by the splitting of old twigs, but the 
more general method — certainly in corals — is by the bursting 
of buds. 
In conclusion I would venture to remark that Mr Bernard’s 
method of classifying forms would receive a more scientific 
foundation, if it were built on a correlation of his forms with 
the physical conditions of their environment, i.e. on habitat , as 
influencing variability rather than on locality. In any case the 
new unit appears to me to be quite unnecessary — even if scienti- 
fically accurate (which, I consider, it is not) — and harmful, in that 
if adopted, it would tend to obscure facts and the reasonable 
deductions therefrom. It would prevent for all time the rearing 
up of our superstructure on a firm foundation, and is calculated 
to materially hinder enquiry — the offspring of speculation — into 
the means by which our tree sprung up and grows. 
If Mr Bernard cannot satisfactorily classify his forms, I may 
perhaps venture to point out that he has not yet come to the 
limits of enquiry into the structure of the Madreporaria. The 
Porifera were formerly classified practically entirely by the form 
of their skeleton, and the examination of their soft parts — a far 
more difficult task — has yielded valuable results of the highest 
scientific importance. The Hexactiniae, from which the Madre- 
poraria are almost certainly derived, are necessarily classified 
entirely by means of the polyp-structure. For the Madreporaria 
the skeleton — a later and an entirely extra-mural structure, as 
shown by Mr Bourne, whose observations I can fully confirm — 
is alone examined. The most careful investigation of the co- 
rallum is desirable, so as if possible to trace how far and the 
means by which our living forms may have been evolved from 
the fossil. Yet by this means we cannot ever hope to get more 
than a short way back. 
Ought not rather every character, especially such as be speci- 
fically variable, to be taken into account in systematic biology ? 
Mr Bernard makes no attempt to put this into operation, and yet 
admits the proposition : — “ And here in passing I should like to 
remark that I am only developing the teaching of my honoured 
friend and teacher Prof. Ernst Haeckel, who 30 years ago in his 
Biologie der Kalk Schwdmme insisted that classification was worth- 
less unless based upon profound morphological study. It is the 
