OCR Text |
Show 1873.] CHARACTERS IN THE CHIROPTERA. 245 nipples ; but I observed that they moved about with great energy from one teat to another. Besides the specimens collected I examined about forty other females; and each had only one young." Dr. Anderson saw nothing, he informs me, to lead him to believe that the young obtained nourishment from the pubic teats, save that they occasionally attached themselves to them. Probably the young Megaderms held on to these teat-like organs as every young animal will attach itself to any thing resembling the nipple of its mother. W e find the next most remarkable secondary sexual differences among the Noctilionidee, especially in the genus Taphozous, Geoff. In this genus the males and females of most species are distinguished by well-marked secondary sexual characters. In Taphozous longimanus, Hardwicke, a species very common about Calcutta, the males are provided with a deep gular pouch, placed between the angles of the mandible, and opening anteriorly by a crescentic margin. This sac contains a yellowish, unctuous, fetid substance, on which the peculiar odour of the animal appears Taphozous longimanus. in a great measure to depend. In the female no sac exists, but a thin semicircular fold of skin marks the position of the opening as found in the males. In T saccolcemus, Geoff., a similar sexual difference is met with ; but the gular pouch, though relatively much smaller in the female, is not reduced to such a rudimentary condition as in T. longimanus. In T. kachhensis, Dobson, the gular pouch is represented in the male by a sligh^y raised semicircular fold of skin (in the position occupied by the opening of the pouch in other species) and surrounding nakedness of the integument; while in the female the skin is quite smooth in the same place. Thus the transition from species possessing a well-developed gular pouch to those in which it is altogether absent is gradual. In Dr. J. E. Gray's " Synopsis of the genera of Vespertilionidae and Noctilionidse" "(Ann. & Mag. Nat. Hist. 1866, p. 92) those species possessing a gular pouch are separated into a distinct genus, under the name of " Saccolaimus." According to this principle we should be obliged to place the males of T. longimanus in one genus, and the females in another ; and, indeed, this is what Dr. L. Fitzinger has lately done. |