i. 147;

of the early progenitors of man, i. 206; greater variability of the, in men than in women, i. 275.

MUSCULUS STERNALIS, Prof. Turner on the, i. 19.

MUSIC, i. 232; of birds, ii. 51; discordant, love of savages for, ii. 67; different appreciation of, by different peoples, ii. 333; origin of, ii. 333, 337; effects of, ii. 335.

MUSICAL cadences, perception of, by animals, ii. 333; powers of man, ii. 330 _et seqq._

MUSK-DEER, canine teeth of male, ii. 241, 256, 257; male, odoriferous organs of the, ii. 280; winter change of the, ii. 299.

MUSK-DUCK, Australian, ii. 38; large size of male, ii. 43; of Guiana, pugnacity of the male, ii. 43.

MUSK-OX, horns of, ii. 247.

MUSK-RAT, protective resemblance of the, to a clod of earth, ii. 298.

_Musophagae_, colours and nidification of the, ii. 171; both sexes of, equally brilliant, ii. 177.

MUSSELS opened by monkeys, i. 140.

_Mustela_, winter change of two species of, ii. 298.

MUTILATIONS, healing of, i. 13.

_Mutilla europaea_, stridulation of, i. 366.

MUTILLIDAE, absence of ocelli in female, i. 341.

_Mycetes caraya_, polygamous, i. 266; vocal organs of, ii. 277; beard of, ii. 283; sexual differences of colour in, ii. 290; voice of, ii. 332.

_Mycetes seniculus_, sexual differences of colour in, ii. 290.

MYRIAPODA, i. 339.

N.

NAEGELI, on the influence of natural selection on plants, i. 152; on the gradation of species of plants, i. 227.

NAILS, coloured yellow or purple in part of Africa, ii. 339.

NAPLES, greater proportion of female illegitimate children in, i. 301.

NARWHAL, tusks of the, ii. 242, 248.

NASAL cavities, large size of, in American aborigines, i. 119.

NASCENT organs, i. 18.

NATHUSIUS, H. von, on the improved breeds of pigs, i. 230; on the breeding of domestic animals, ii. 370.

NATURAL selection, its effects on the early progenitors of man,