"III. The reasons for and against believing that such races have really been produced, forming what are called species." It will be seen that Chapter III as originally designed corresponds to Part II (p. 22) of the Essay of 1842, which is (p. 7) defined by the author as discussing "whether the characters and relations of animated things are such as favour the idea of wild species being races descended from a common stock." Again at p. 23 the author asks "What then is the evidence in favour of it (the theory of descent) and what the evidence against it." The generalised section of his Essay having been originally Chapter III{22} accounts for the curious error which occurs in pp. 18 and 22 where the second Part of the Essay is called Part III. {22} It is evident that _Parts_ and _Chapters_ were to some extent interchangeable in the author's mind, for p. 1 (of the MS. we have been discussing) is headed in ink Chapter I, and afterwards altered in pencil to Part I. The division of the Essay into two parts is maintained in the enlarged Essay of 1844, in which he writes: "The Second Part of this work is devoted to the general consideration of how far the general economy of nature justifies or opposes the belief that related species and genera are descended from common stocks." The _Origin of Species_ however is not so divided. We may now return to the question of the date of the Essay. I have found additional evidence in favour of 1842 in a sentence written on the back of the Table of Contents of the 1844 MS.--not the copied version but the original in my father's writing: "This was written and enlarged from a sketch in 37 pages{23} in Pencil (the latter written in summer of 1842 at Maer and Shrewsbury) in beginning of 1844, and finished it <_sic_> in July; and finally corrected the copy by Mr Fletcher in the last week in September." On the whole it is impossible to doubt that 1842 is the date of the earlier of the two Essays. {23} On p. 23 of the MS. of the _Foundations_ is a reference to the "back of p. 21 bis": this suggests that additional pages had been interpolated in the MS. and that it may once have had 37 in place of 35 pp. The sketch of 1842 is written on bad paper with a soft pencil, and is in many parts extremely difficult to read, many of the words ending in mere scrawls and being illegible without context. It is evidently written rapidly, and is in his most elliptical style, the articles being frequently omitted, and the sentences being loosely composed and often illogical in structure. There is much erasure and correction, apparently made at the moment of writing, and the MS. does not give the impression of having been re-read with any care. The whole is more like hasty memoranda of what was clear to himself, than material for the convincing of others.