"Why does individual die? To perpetuate certain peculiarities (therefore adaptation), and obliterate accidental varieties, and to accommodate itself to change (for, of course, change, even in varieties, is accommodation). Now this argument applies to species.
"If individual cannot propagate he has no issue—so with species.
"If SPECIES generate other SPECIES, their race is not utterly cut off:— like golden pippins, if produced by seed, go on—otherwise all die.
"The fossil horse generated, in South Africa, zebra—and continued—perished in America.
"All animals of same species are bound together just like buds of plants, which die at one time, though produced either sooner or later. Prove animals like plants—trace gradation between associated and non-associated animals—and the story will be complete."
Here we have the view already alluded to of a term of life impressed on a species.
But in the following note we get extinction connected with unfavourable variation, and thus a hint is given of natural selection:
"With respect to extinction, we can easily see that [a] variety of [the] ostrich (Petise), may not be well adapted, and thus perish out; or, on the other hand, like Orpheus The first part of the next extract has a similar bearing. The end of the passage is of much interest, as showing that he had at this early date visions of the far-reaching character of the theory of evolution:— "With belief of transmutation and geographical grouping, we are lead to endeavour to discover CAUSES of change; the manner of adaptation (wish of parents??), instinct and structure becomes full of speculation and lines of observation. View of generation being condensation (I imagine him to mean that each generation is "condensed" to a small number of the best organized individuals.) test of highest organisation intelligible...My theory would give zest to recent and fossil comparative anatomy; it would lead to the study of instincts, heredity, and mind-heredity, whole [of] metaphysics.