340 J. D. Dana on Z oophytes. 
organ may fail without requiring an entire separation of an indi- 
vidual from the group. 
o classify, requires therefore the widest possible range of 
knowledge of organic beings, and the nicest balancing of affini- 
ties: and we remark again that it consists rather in expressing the 
various chains of affinities or homologies direct and parallel, with 
their shadings and blendings, than in searching for certaim mv10- 
lable characteristics for distinguishing groups of species. 
Classification of Zoophytes.—In view of the foregoing prin- 
ciples, any classification of Zoophytes made out without refer- 
ence to the structure of the animals must necessarily be faulty. 
There have been several of this kind in the department of corals ; 
and as the subject has been little understood till within a few 
years past, their errors were to be expected. ‘They subserved, for 
the time, the purpose of systematizing the facts known, an al- 
forded a means of characterizing species: so far, they were good. 
But at the present day, to make out a classification based on the 
corals alone and the easiest method of distinguishing them, 
the species should be first studied, and afterwards such characters 
os down for the corals, as belong to the orders and families thus 
educed. j 
The first classification of Zoophytes in which the anna 
ceived attention, was offered by Blainville.* Lamarck had 
Af ott i Apoidea 
~~ * Manuel d’Actinologie ou de Zoophytologie, par H. M.D. de Blainville. an 
pp. 8vo, with an atlas of 100 plates. Paris, 1834. (The printing began 1» 
