64 THE DESCENT OF MAN 



canines f ullj developed ; but in tlie female gorilla, and in a 

 less degree in the female orang, these teeth project consid- 

 erably beyond the others; therefore the fact, of which I have 

 been assured, that women sometimes have considerably pro- 

 jecting canines, is no serious objection to the belief that their 

 occasional great development in man is a case of reversion 

 to an apelike progenitor. A He who rejects with scorn the 

 belief that the shape of his own canines, and their occasional 

 great development in other men, are due to our early fore- 

 fathers having been provided with these formidable weapons, 

 will probably reveal, by sneering, the line of his descent. 

 For though he no longer intends, nor has the power, to use 

 these teeth as weapons, he will unconsciously retract his 

 "snarling muscles" (thus named by Sir 0. Bell)," so as to 

 expose them ready for action, like a dog prepared to fight.X, 



Many muscles are occasionally developed in man, which 

 are proper to the Quadrumana or other mammals. Prof. 

 Vlacovich*' examined forty male subjects, and found a mus- 

 cle, called by him the ischio-pubic, in nineteen of them; in 

 three others there was a ligament which represented this 

 muscle; and in the remaining eighteen no trace of it. In 

 only two out of thirty female subjects was this muscle de- 

 veloped on both sides, but in three others the rudimentary 

 ligament was present. This muscle, therefore, appears to 

 be much more common in the male than in the female sex; 

 and on the belief in the descent of man from some lower 

 form, the fact is intelligrble; for it has been detected in 

 several of the lower animals, and in all of these it serves 

 exclusively to aid the male in the act of reproduction, 



Mr. J. Wood, in his valuable series of papers," has 



*" "The Anatomy of Expression," 1844, pp. 110, 131. 



" Quoted by Prof. Canestrini in the "Annuario," etc., 1867, p. 90. 



"^ These papers deserve careful study by any one who desires to learn how 

 frequently our muscles vary, and in varying come to resemble those of the 

 Quadrumana. The following references relate to the few points touched on 

 in my text: "Proc. Eoyal Soc, vol. xiv., 1865, pp. 379-384; vol. xv., 1866, 

 pp. 241, 242; vol. xv., 1867, p. 544; vol. xvi., 1868, p. 524. I may here add 

 that Dr. Murie and Mr. St. George Mivart have shown in their Memoir on the 

 lemuroidea ("Transact. Zoolog. Soc," vol. Vii., 1869, p. 96) how extraordinarily 



