Chap. XIV. 
CONCLUSION. 
487 
pedigrees or armorial bearings; and we have to dis- 
' cover and trace the many diverging lines of descent in 
onr natural genealogies, by characters of any kind which 
have long been inherited. Eudimentary 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 
living fossils, will aid us in forming a picture of the 
ancient forms of life. Embryology will reveal to us the 
structure, in s6me 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 de¬ 
scended from one parent, and have migrated from some 
one biidhplace; 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 of the 
inhabitants of the sea on the opposite sides of a conti¬ 
nent, and the nature of the various inhabitants of that 
continent in relation to their apparent means of immigra¬ 
tion, 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 embedded 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 formation will be recognised as 
having depended on an unusual concurrence of circum¬ 
stances, and the blank intervals between the successive 
stages as having been of vast duration. But we shall 
