32 INTRODUCTION 



fortunately, paid more attention to the subject and have proved 

 conclusively that in their country the normal breeding season is 

 autumn. At that season spermatozoa are found numerously 

 in the uterus of the adult female, and the organs of the male 

 are also functional. Ovulation is, however, postponed until the 

 termination of hibernation, during which period the ovaries are 

 quiescent, but the spermatozoa retain their activity in the 

 uterus until fertilisation takes place in April. On this point all 

 authorities are agreed, and the facts, subject to correction as to 

 details, may be taken as substantiated. An alternative view, 

 that ovulation and fertilisation may take place in the autumn and 

 winter, with subsequent postponement of the development of the 

 embryo, seems to be unsupported by facts. 



A point still open to discussion is the occurrence of copula- 

 tion in spring. Messrs RoUinat and Trouessart, whose observa- 

 tions, as briefly summarised below, are the most complete in 

 existence, altogether deny that it takes place even in the case of 

 a female which has missed autumnal impregnation. They 

 admit, however, the evident ability of the male, and the fact 

 remains that acts of courtship have been reported in spring, as 

 in Wales by Mr T. W. Proger, for the Lesser Horseshoe ; his 

 observations, however, are not definite as to consummation. 

 Again, in France, Monsieur M, Duval ^ has noticed such acts 

 amongst captive bats, but it is possible that they may have been 

 abortive, and observations on captive animals are rarely of 

 value on such points. The matter deserves further study, but 

 since the breeding season may vary with locality and climate, 

 conflicting reports from observers in different countries are 

 naturally to be expected. 



The work of Messrs Rollinat and Trouessart^ is based 

 partly upon a study of a non- British bat, the Mouse-eared,' and 



myosotis, mystacinus, nattereri, bechsteini, auritus, barbastellus, hippodderos) : Carl 

 Vogt, Association frangaise pour I'avancement des Sciences, sess. lo, Alger, 1881, 

 Compte rendu, 655-662 : thus including all British species except leisleri. 



' Etudes sur V Embryologie des Chiroptires, i, Paris, 1879. For a description of 

 copulation, which takes place while the animals are at rest, not in flight, see Hahn, 

 op. cit, i6l ; Victor Fatio, "Vertebras de la Suisse," i., 23, 1869; Duval, "Sur 

 I'accouplement des Chauves-Souris," in Comptes rendus Soc. Biol., Paris, 23rd Feb. 

 189s, 135-136. 



2 " Sur la reproduction des Chauves-Souris," Mem. Soc. Zool. de Frame, ix., 214- 

 240,1896. ^ Myotis myosotis. 



