OF VARIETIES IN FORM. 383 



observation already made and exemplified in speaking of 

 colour ; namely, that the law of resemblance between pa- 

 rents and offspring, which preserves species, and maintains 

 uniformity in the living part of creation, suffers occasional 

 and rare exceptions ; that, under certain circumstances, an 

 offspring is produced with new properties, different from 

 those of the progenitors ; and that the most powerful of 

 these causes Is that artificial mode of life which we call the 

 state of domestication. 



A question here naturally suggests itself, how this comes 

 about? How does It happen that any circumstances In the 

 mode of life Influence the result of the generative process ? 

 The reply to this Inquiry must be deferred until the internal 

 mechanism of the animal motions shall be more completely 

 laid open ; until we are able to shew how the capillaries of 

 the mother form the germ of a new being out of materials 

 presented by the common mass of nutritive fluid ; and how 

 the vessels of this embryo, when more advanced, fashion 

 the nutritive supply derived from the mothers Into a new set 

 of organs, and give to the whole a more or less accurate 

 resemblance to the bodies of both parents. At present we 

 can only note the fact, that the domestic condition produ- 

 ces in great abundance, not only those deviations from the 

 natural state of the organization which constitute disease, 

 but also those departures from the ordinary course of the 

 generative functions which lead to the production of new 

 characters In the offspring, and thus lay the foundation of 

 new breeds. The domestic sow produces young twice 

 a-year ; the wild animal only once. The former frequently 

 brings forth monstrous foetuses, which are unknown In the 

 latter. Oar pigs, too, are invaded by a new kind of hy- 

 datids *, dispersed -through the substance of all the organs, 

 constituting what is called the measles in pork. The 

 creation of these must be referred to an epocha posterior to 

 that of the species in which they are found, as they do not 

 exist In its natural state. 



* They are represented by BLU:in:Ni3ACH, in his Jbbildungen Natur-His- 

 torischcr Gegenstdnde ; No. 39. 



