Transcriber’s notes:

In this transcription, page numbers are shown in the rightmargin, and page footnotes (renumbered in consecutive order) aregrouped together at the end of the book. Hyperlinks to footnotesand page references are indicated by black dotted underlines plusaqua highlighting when the mouse pointer hovers over them. Thefootnotes are themselves hyperlinked back to the originating markerto facilitate easy return to the text. A red dashed underline asshown here indicates the presence of atranscriber’s comment; scrolling the mouse pointer over such textwill reveal the comment.

The rare spelling typos noted in the original text havebeen corrected silently (e.g. invividual-->individual,hyberbola-->hyperbola) but inconsistent use of the ligature æ/ae (e.g.palæontology/palaeontology), inconsistent use of alternative spellings(e.g. learned/learnt), and occasional inconsistencies of hyphenationhave been left as in the original. Minor punctuation typos have beencorrected silently (e.g. index entries with missing commas). Theabbreviation viz. appears in both roman and italic font.

Formatting of entries in the Table of Contents does not accuratelymatch that of the corresponding headings in the text, particularly theheading Pt.I-B-3 which contains an extraneous α.

In Figure 12 caption, multiple ditto marks have been replaced by therelevant text for greater clarity.