Journal: Bibliotheca Sacra
Volume: BSAC 39:153 (Jan 1882)
Article: The Practical Determination Of Species
Author: Leonard Marsh

BSac 39:153 (Jan 1882) p. 51

The Practical Determination Of Species1

Leonard Marsh

Is organic nature one same continuous series of homogeneous forms passing gradually into each other without difference of kind, so that all classification must necessarily be arbitrary and artificial? Or do these living organisms exist in groups, each in some of its attributes essentially other than all the others, distinctly limited and circumscribed by the hand of Nature herself? In the latter case a natural classification is possible if we can discover these essential differences and the limits which Nature has assigned to each group. The existence of such differences would seem to be obvious enough: as for instance between forms of the vegetable and those of the animal kingdom. No one could mistake an oak for an elephant, or a turtle for a cabbage; yet where the two organic kingdoms approach nearest to each other we not only cannot practically separate the organisms which belong to the one of these kingdoms from those which belong to the other, but we do not know in what their essential difference consists.

The very terms we use — animal kingdom, vegetable kingdom; the names of things — tree, grass, beech, pine; horse, bird, fish, etc., show that we do instinctively classify, separate, or endeavor to separate, into groups the multiform bodies of the organic world. Yet the groups indicated by such names are perhaps as often artificial as natural. The

BSac 39:153 (Jan 1882) p. 52

terms “artificial” and “natural” as used in natural history are extremely vague. It is obvious enough that “natural” means according to the plan of nature, and that “artificial” implies human origin. But what is according to the plan of nature, and what is artificial, is often mere matter of opinion. Artificial classification may be only in reference to some practical convenience or utility, without aiming at scientific precision. Or if it aims at scientific ends it fails to give definite and complete circumscription to its groups, or associates their elements in reference to comparatively unimportant common characters, while those in which their essential resemblance consists are separated. If for example we divide plants into trees, shrubs, and herbs, which is a convenient arrangement for some purposes, definite natural limitation is impossible; nature has made no limits; so that we cannot tell, except by an arbitrary line, where the trees end and the shrubs begin, or where the shrubs end and the herbs begin. Or we may associate among flowering plants all those which have opposite leaves and all those whose leaves are alternate. The limitation is definite, but the common characters are wholly unimportant. In all attempted natural syst...