Geographical Distribution of Crustacea. 357 
to deny the agency of voluntary or involuntary migration in pro- 
ducing this dissemination. An example of this, beyond all dis- 
pute, is that of the Mediterranean Sea and Japan. No water 
communication for the passage of species can be imagined, An 
opening into the Red Sea is the only possible point of intercom- 
munication between the two kingdoms; but this opens into the 
Torrid zone, in no part of which are the species found. The | 
two regions have their peculiarities and their striking resemblan- 
ces; and we are forced to attribute them to original creation and 
not intercommunicati 
X. The tiie gy Beir are not merely in the existence 
of a few identical s ere are genera common to 
two seas that occur sth else in the Oriental kingdom, as 
Latreillia, Ephyra, Sicyonia, &c.; and species where not iden- 
tical have an exceedingly close resemblance, 
Now this resemblance in genera and species (without exact 
identity in the latter) is not explained by supposing a possible 
mitercommunication. But we may reasonably account for it on 
the ground of a — in the temperature and other physical 
conditions of the seas; and the well-known principle of “like 
causes, like effects” crass itself upon the mind as fully meeting 
the case. Mere intercommunication could not produce the re- 
semblance; for just this similarity of physical condition would 
still be necessary, And where such a similarity exists, creative 
power may multiply analogous species; we should almost say, 
identity of genera in @ given ba and even Ke, specific structure 
or of subge 
If, then, ihe similarity i in the characters of these regions is the 
occasion of the identity of ap and of the very close likeness 
in certain species (so close an identity is sometimes strongly 
suspected where not tae we must conclude that there is a 
— of actual identity of species, through original creation, 
This, in fact, becomes the only admissible view, the actually 
identical species between Japan and the Mediterranean are ex- 
amples. 
XL When we find a like resemblance of genera and species 
able from the common P, squilla of Europe, and is one example 
of this resemblance. It may not be an identity; and on this ac- 
