Elements of comparative anatomy / by Carl Gegenbaur ; translated by F. Jeffrey Bell ; the translation revised and a preface written by E. Ray Lankester.
- Carl Gegenbaur
- Date:
- 1878
Licence: Public Domain Mark
Credit: Elements of comparative anatomy / by Carl Gegenbaur ; translated by F. Jeffrey Bell ; the translation revised and a preface written by E. Ray Lankester. Source: Wellcome Collection.
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![ence of the transmission of properties, and recognise in it a plisenomenon of general prevalence^ wliicli may indeed present modifications of, but never exceptions to, certain definite laws. We may deduce it from tlie conditions involved in propagation, and tlius explain it to a certain degree; for it is clear that portions of an organism, if they give rise to a new organism, will carry on to it the peculiarities which the primitive organism possessed. This is clearest in the lower organisms, which are propagated by mere division. Each portion forms at once an organism like the first. But from this there extends a continuous series of methods of pro- pagation, up to those in which generative products come into action, which are quantitatively very different, although in all cases derived from the division of the parent organism. The new organism in this case also represents in actual sub- stance the continuation of the ancestral, and will therefore possess qualities which agree with those of the latter. The amount of similarity or agreement in the organisation of animals is very various. We recognise animals which differ from one another by slight points only; then those which are separated by considerable differences ; and again others which, in external or internal organisation, present the greatest differences. Thus agreement, as well as variation, is found in interminable gradations. We call things which are more or less like to one another, related; and in like manner, when organisms exhibit likeness, we use that word to denote the reciprocal connection, but in this case we give to it its full meaning of blood-relationship. We recognise similar organisms as related to one another, when we can explain the similarity of the organisation by common inheritance. But the degree of this similarity measures the degree of relationship which we can deduce from it. Eelationship can be regarded as close when the differences are slight; while when the differences are great it must be regarded as more distant. We thus substitute for the conception of the agreement, or likeness, of the organisation, that of relationship, for we regard the agreements which obtain in the organisation of a collection of organisms as inherited peculiarities. The doctrine of the Blood-relationship of Organisms or Phy- logeny is based on the law of inheritance. Comparative anatomy thus reveals the relations of affinity within the various divisions of the Animal Kingdom by pointing out what is alike and what unlike. [A full account of this most important law of inheritance and its phsenomena is to be found in HÄckel^s luminous essay on the subject (Generelle Morphologie, vol. ii. p. 170).]](https://iiif.wellcomecollection.org/image/b20417202_0039.jp2/full/800%2C/0/default.jpg)
