Mathematical Contributions to the Theory of Evolution. 27;} 



Bellamy Clifton, M.A. ; William Turner Thiselton Dyer, C.M.G. ; 

 Professor James Alfred Ewiiig, M.A. ; Lazarus Fletcher, M.A. ; Walter 

 Holbrook Gaskell, M.D. ; Professor Alfred George Greenhill, M.A 

 William Huggins, D.C.L. ; Professor Charles Lapworth, LL.D. \ 

 Major Percy Alexander MacMahon, R.A.; Professor Raphael Meldola', 

 F.C.S.; Professor William Ramsay, Ph.D. ; The Lord Walsinglmm' 

 M.A. ; Professor Walter Frank Raphael Weldon, M.A. ; Admiral 

 William James Lloyd Wharton, C.B. 



The following Papers were read: 



I. "Mathematical Contributions to the Theory of Evolution. On 

 Telegony in Man, &c." By KARL PEARSON, F.R.S., University 

 College, with the assistance of Miss ALICE LEE, Bedford 

 College, London. 



II. " On the Magnetic Permeability of Liquid Oxygen and Liquid 

 Air." By J. A. FLEMING, M.A., D.Sc., Professor of Electrical 

 Engineering in University College, London, and JAMES DEWAK, 

 LL.D., F.R.S., Fullerian Professor of Chemistry in the Royal 

 Institution. 



" Mathematical Contributions to the Theory of Evolution. On 

 Telegony in Man, &c." By KARL PEARSON, F.R.S., Uni- 

 versity College, with the assistance of Miss ALICE LEE, 

 Bedford College, London. Received August 27, Read 

 November 26, 1896. 



(1) The term telegony has been used to cover cases in which a 

 female A, after mating with a male B, bears to a male C offspring 

 having some resemblance to or some peculiar characteristic of A's 

 first mate B. The instances of telegony usually cited are (i) cases 

 of thoroughbred bitches when covered by a thoroughbred dog t 

 reverting in their litter to half-breds, when they have been previously 

 crossed by dogs of other races. Whether absolutely unimpeachable 

 instances of this can be produced is, perhaps, open to question, but 

 the strong opinion on the subject among dog-fanciers is at least 

 remarkable; (ii) the case of the quagga noted by Darwin (see 

 * Origin of Species,' 4th edition, p. 193), and still more recently 

 (iii) a noteworthy case of telegony in man cited in the 'British 

 [edical Journal' (see No. 1834, February 22, 1896, p. 462). 

 In this latter case a very rare male malformation, which occurred, 

 in the male B, was found in the son of his widow A, by a second 

 msband C. Here, as in the other cases cited, a question may always- 

 raised as to the possibly unobserved or unknown occurrence of the 



