But as we have no written pedigrees you will, perhaps, say this will not help much; but I think it ultimately will, whenever heterodoxy becomes orthodoxy, for it will clear away an immense amount of rubbish about the value of characters, and will make the difference between analogy and homology clear.

The time will come, I believe, though I shall not live to see it, when we shall have very fairly true genealogical trees of each great kingdom of Nature.
LETTER 59.

TO T.H.HUXLEY.

Down, December 16th [1857].
In my opinion your Catalogue (59/1.

It appears from a letter to Sir J.D.Hooker (December 25th, 1857) that the reference is to the proofs of Huxley's "Explanatory Preface to the Catalogue of the Palaeontological Collection in the Museum of Practical Geology," by T.H.Huxley and R.
Etheridge, 1865.