232 RHINOLOPHID^— RHINOLOPHUS 



organs are very similar to those of the older females, but the right horn 

 of the uterus, although sHghtly longer, is no larger than the left, and the 

 false nipples are much smaller. One of these second-year females had 

 not yet paired on 27th October. The " bouchon " is never formed in the 

 females of the first year, and comparatively late in those of the second 

 year. 



Contrary to the views of Carl Vogt {Association frangaise pour 

 I'avancemeHt des Sciences, x. ; Compte rendu, 655, Algiers, 1881), 

 Rollinat and Trouessart find no evidence that the young females pair 

 in the spring of their second year ; they are sure that they do not do so 

 until their second autumn ; some, perhaps, not till the third. 



The males undergo a season of rut, their organs being well 

 developed from September to May. The urethral gland, a structure 

 peculiar to these bats and of doubtful function, is then of enormous 

 size, although in the non-breeding season inconspicuous. Since the 

 organs remain functional not only during autumn — the pairing season — 

 but also throughout the winter and a part of the spring, it seems 

 natural to suppose that copulation takes place during the latter periods. 

 This suggestion, advanced by Robin {Bull, de la Soc. Phil, de Paris (7), 

 v., 26th March 1881, 88), and at first supported by Rollinat and Troues- 

 sart, was later rejected by them on the ground of the existence of so great 

 a number of virgin females just under a year old in April and May. 

 The enormous reserve of apparently wasted spermatozoa is in this 

 case a puzzling factor, but the authors suggest that it may be 

 reabsorbed and utilised in accordance with the Brown-S6quard theory 

 as an internal secretion. The presence of the " bouchon ' in fertilised 

 females must prevent subsequent copulation in winter and spring. 



Young males, although possessing spermatozoa in their second 

 autumn, probably do not breed until their third, when they are a little 

 over two years old. 



In the urethra of many males there occurs a sort of soft " bouchon," 

 the function and origin of which is uncertain. It is possible that in 

 bats, as in some rodents,^ the secretion of the prostate gland has power 

 to coagulate the mucous secretion of the vagina, and the beginning of 

 coagulation may take place in the urethra of the male. 



Description : — The general appearance of this bat is typical of its 

 genus. In size it about equals the Noctule or Serotine. 



The head (Plate XVIII., Fig. 4) is long, the occiput large and 

 rounded, the muzzle very tumid and furnished with long, stiff hairs. 

 The mouth opens straight and wide. The lower lip has a single groove 

 and occasionally traces of two others, one on either side. 



The ear (Fig. 2, No. 10, p. 7) is rather large, broad at the base, and 



' L. Camus and E. Gley, Comptes rendus Soc. Biol. (Paris), i8th July i8g6, 

 787. 



