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DR. carpenter’s RESEARCHES ON THE FORAMINIFERA. 
tion afforded by large numbers of specimens, collected (so far as may be possible) 
from different formations, and from different geographical areas. Until the whole of 
this process shall have been carefully and systematically gone through, no limitation 
of a species by a definition of any kind, can be regarded in any other light than as 
a provisional means of rnarhmg-out the existence of a particular type of str ucture, whose 
relationship to other types must be a matter of further investigation. 
75. Let me subjoin such “pregnant instances,” as shall prove the importance of 
each of the foregoing principles, from the result of the violation or neglect of it; — 
(1) so long as external conformation was alone regarded, and no account was 
taken of internal organization, the Nautiloid Foraminifera were placed among 
Cephalopods, and the Coralloid forms among Polypifera ; to neither of which classes 
have they any kind of relationship ; (2) so long as developmental history was un- 
studied, the Hydroid Zoophytes and the Medusoid Acalephae were considered as 
entirely disconnected groups, belonging to two different Zoological classes, instead 
of (as in reality) different states of the very same organisms ; (3) so long as reliance 
is placed on the comparison of a few individual specimens only, without any account 
being taken of the intermediate forms by which the more divergent types may be 
connected, so long are species multiplied to a most unwarrantable excess, as is found 
to be the case in almost every department of Zoology and Botany by those who 
devote themselves to a more extended comparison; thus, nineteen species have been 
made from the common Potatoe, and many more from the Solanum nigrum ; so, 
multitudes of species have been instituted in various genera of Californian shells, 
by the late Mr. C. B. Adams, whose identity is established by a more extended 
comparison of individuals (as will be shown in a Report which is being prepared at 
the request of the British Association, by my brother, the Rev. P. P. Carpenter) ; 
in fact, wherever this test is conscientiously applied, its effect is to reduce the number 
of reputed species, sometimes in a most remarkable degree*. (4) In like manner it 
has been by comparing only a small number of specimens from remote geographical 
provinces, and by neglecting the intermediate varieties that present themselves even 
among sufficiently large collections from these, still more among specimens collected 
from intervening regions, that not only numerous errors of detail have been com- 
mitted, but general doctrines have been propounded, which the advance of Science 
has proved to be utterly untenable. As an example of the former kind, maybe cited 
the facts mentioned by Dr. J. D. Hooker {op. cit.), that of the New Zealand varieties 
of Oxalis corniculata, one of the most widely-diffused and most variable Flowering 
plants in the world, no less than seven or eight species have been made, neither of 
them supposed to be identical with any belonging to the European Flora ; whilst Pteris 
* I am most glad to find my views on this point in accordance with those of Dr. Joseph D. Hooker (see 
his ‘ Introductory Essay on the Flora of New Zealand,’ § 2), who has been led to the conviction, that instead 
of affirming the existence of 100,000 species of known Plants, we ought not to reckon more than half that 
number. 
