Morphology of the Mammalian Ossicula auditûs.

THE complete memoir on the small ear‐bones of the Mammals will hereafter be published in the Society's ‘Transactions’ with copious illustrations, whereby an excellent comparison of the various forms peculiar to and significant of groups may be instituted. Previously elsewhere ? I have given a short résumé respecting the material which has afforded the means of study of the series, with a brief reference to what has already been published on the internal auditory apparatus, and added a short notice concerning points among certain of the higher groups of the Mammalia. For the present abstract I shall therefore confine my remarks to the auditory ossicles of the following orders, viz.:–the Insectivora, the Chiroptera, the Cetaeea, the Sirenia, the Edentata, the Marsupialia, and the Monotremata.     

Grooming-at-a-distance by exchanging calls in non-human primates

The ‘social bonding hypothesis'' predicts that, in large social groups, functions of gestural grooming should be partially transferred to vocal interactions. Hence, vocal exchanges would have evolved in primates to play the role of grooming-at-a-distance in order to facilitate the maintenance of social cohesion. However, there are few empirical studies testing this hypothesis. To address this point, we compared the rate of contact call exchanges between females in two captive groups of Japanese macaques as a function of female age, dominance rank, genetic relatedness and social affinity measured by spatial proximity and grooming interactions. We found a significant positive relationship between the time spent on grooming by two females and the frequency with which they exchanged calls. Our results conform to the predictions of the social bonding hypothesis, i.e. vocal exchanges can be interpreted as grooming-at-a-distance.