526 ORIGIN OF SPECIES 



opened, on the causes and laws of variation, on correlation, 

 on the effects of use and disuse, on the direct action of ex- 

 ternal conditions, and so forth. The study of domestic pro- 

 ductions will rise immensely in value. A new variety raised 

 by man will be a more important and interesting subject for 

 study than one more species added to the infinitude of already 

 recorded species. Our classifications will come to be, as far 

 as they can be so made, genealogies ; and will then truly give 

 what may be called the plan of creation. The rules for 

 classifying will no doubt become simpler when we have a 

 definite object in view. We possess no pedigrees or armorial 

 bearings; and we have to discover and trace the many di- 

 verging lines of descent in our natural genealogies, by char- 

 acters of any kind which have long been inherited. Rudi- 

 mentary organs will speak infallibly with respect to the 

 nature of long-lost structures. Species and groups of species 

 which are called aberrant, and which may fancifully be 

 called Hving fossils, will aid us in forming a picture of the 

 ancient forms of life. Embryology will often reveal to us 

 the structure, in some degree obscured, of the prototypes of 

 each great class. 



When we can feel assured that all the individuals of the 

 same species, and all the closely allied species of most genera, 

 have within a not very remote period descended from one 

 parent, and have migrated from some one birth-place; and 

 when we better know the many means of migration, then, by 

 the light which geology now throws, and will continue to 

 throw, on former changes of climate and of the level of the 

 land, we shall surely be enabled to trace in an admirable 

 manner the former migrations of the inhabitants of the whole 

 world. Even at present, by comparing the differences be- 

 tween the inhabitants of the sea on the opposite sides of a 

 continent, and the nature of the various inhabitants on that 

 continent in relation to their apparent means of immigration, 

 some light can be thrown on ancient geography. 



The noble science of Geology loses glory from the extreme 

 imperfection of the record. The crust of the earth with its 

 imbedded remains must not be looked at as a well-filled 

 museum, but as a poor collection made at hazard and at rare 

 intervals. The accumulation of each great fossiliferous for- 



