Notes on the Genitalia and Reproduction of some African Rats

Summary.1 The anatomy and histo‐physiology of the genitalia of nine species of African bats arc described. The species are Cælura afra Peters, Taphozous sp. indet. (Fam. Emballonuridæ); Nycteris luteola Thos. and N. hispida Schreb. (Fam. Nycteridae); Cardioderma cor Peters (Fam. Megadermidæ); Hippo‐sideros caffer Sund. and Triænops afer Peters (Fam. Hipposideridæ): Miniopterus minor Peters and M. dasythrix Temm. (Fam. Vespertilionidæ). 2 The glans penis is large and complicated in structure in C. cor and T. afer , smaller in N. luteola, N. hispida and H. caffer , and minute in Taphozous, M. minor and M. dasythrix . The prepuce is tJhin and retractile in the first five; thick and glandular in the last three. 3 An os penis of complicated architecture is present in N. lutebla, C. cor and T. afer . It is of simple form in N. hispida, Taphozous and H. caffer . It is comparatively large in the first four species and extends into the penis proximal to the glans. In the last two it is minute and confined to the glans. There is no os penis in M. minor and M. dasythrix . 4 Accessory erectile bodies, in addition to the corpora cavernosa and corpus spongiosum, are present in all species. They are particularly conspicuous in N. luteola and C. cor . The corpora cavernosa are fused for the whole or part of their length in all species; in some they are separated by a septum of tunica albuginea, in others they are completely fused. 5 The scrotum is post‐anal, the testes are oval and the epididymides have long tails in M. minor and M. dasythrix . The testes and epididymides are similar but lie beneath the integument of the base of the penis in immature specimens of Taphozous . The scrotum is pre‐anal, the testes are subglobular and the cpididymides do not have greatly elongated tails in N. luteola and C, cor . The testes and epididymides are similar in form in N. hispida and H. caffer , but in T. afer , though the testcts are subglobular, the tails of the epididymides are long. In the first species they lie in the inguinal canals at the sides of the base of the penis; in the last two cranial to the base of the penis. In all three free spermatozoa are present in the genital tract. It is possible that the testes have been withdrawn from pre‐anal scrotal pouches, though no structural evidence for this was found. 6 Vesiculz seminales are present in T. afer and Taphozous . They are large glandular bodies, whose ducts open into the urethra near the openings of the vasa efferentia in T. afer , and unite with the vasn efferentia near their openings in Taphozous . Vesiculs seminales are absent in the other species. 7 The ampulls of Henle are reprcsented by a slight convolution of the vas deferens in T. afer and by small glandular swellings in Taphozous . In all the othert. species they are large glandular swellings of the ends of the vasa deferentia and are comparable in structure with the vesiculæ seminales in the two species where those bodies occur. In H. caffer they are divided into two unequal lobes. 8 The prostate is a large glandular mass below the neck of the bladder. It surround.r the uretbra, having large anterior and posterior lobes, in all species except N. luteola and N. hispida . In the latter two species it is confined to the posterior surface of the urethra. In several species the ampullæ of Henle are partly embedded in the prostate. 9 The urethral gland is large in C. cor and H. caffer , small in T. afer, M, minor and N. dasythrix . It is absent, in Taphozous, N, luteola and N. hispida . 10 A utriculus prostaticus is present in Taphozous, N. luteola: H. caffer and C. cor . Tt is comparatively large in Taphozous and ends in a number of divorticula; it is small and simple in the other three. No sign of a utriculus prostaticus was found in N. hispida., T. afer, M. minor or M. dasythrix . 11 Cowper's glands are comparatively large in all species. 12 The vulvar opening is transverse in all species. The clitorideal pad is large in C. cor and T. afer , less developed in C. afra, N. luteola and N. hispida , and small in Taphozous, M. minor and M. dasythrix . 13 Pubic teats, unoonnected with a mammary gland, are present in C. cor and T. afer . In both species they contain canals which are identical in histo‐logical appearance with true milk‐ducts. The canals end blindly at the base of the teats. No pubic teats occur in the other species. Rudimentary pubic teats are present in the males of C. cor . 14 The uterine cornua are approximately equal in size in C. afra . One corm is slightly larger, on the right side in Taphozous and N. hispida , and on the right or left side in N. luteola and T. afer . It is considerably larger on the right side in M. minor and M. dasythrix . A pregnancy was present., or had occurred, on the right side in C. afra (one specimcn), N. hispidia (three), M. minor (thirteen), and M. dasythrix: (six). In N. luteola occurrences were: right side, six; left side, seven. In T. afer and C. cor the pregnancy fills the cornua of both sides, together with the body of the uterus which are thrown into one large cavity. Assuming that the pregnancy started on the side to which the placenta is attached, it started in the left side in two specimens of T. afer and once each on the left and right in C. cor . 15 There is no internal uterine body in N. luteola and N. hispida , where each cornu communibates with its own cervical canal which opens separately into the vagina. There is a completely divided Septate uterine body communicating with a singlr cervical canal in Taphozous . The undivided uterine body is very short in T. afer, M. minor and M. dasythrix , and short and wide in C. afra . 16 The epithelium of the vagina is thrown into high loagitudinal ridges in N. luteola, N. hispida, C. cor and T. afer , and into comparatively low ones in the other species. The epithelium becomes strongly cornified at œstrus. In one pregnant specimen of C. afra the urinogenital canal was strongly constricted and its lumen nearly occluded by cornified epithelium. 17 The urethra is asymmetrical, being displaced to the right of the vagina, in the females of C. afra, N. luteola and T. afer . In all the other species it is symmetrical. 18 A “female prostate” is well developed in C. afra, Taphozous, N. luteola and C. cor , less conspicous in M. minor , and absent in N. hispida, T. afer and M. dasythrix . 19 One corpus luteum was present in each ovary of two pregnant C. cor which were near full term. One was present in the ovary of the side of pregnancy in a C. afra containing an early pregnancy. One was present in the ovary of the opposite side from the pregnancy in six X. dasythrix containing unattached blastocpts in the enlarged right cornu. No corpora hitea were present in either ovary of pregnant examples of N. luteola (nine) or T. afer (two). 20 A post partum œstrus occurs in N. luteola . All the nine pregnant specimens were also in full lactation. 21 In the localities of provenance birth occurs approximately at the following times:‐in early December, N. hispida and M. minor ; in early January, C. cor and T. afer; late in January, C. afra ; in Novembw and again late in January, N. luteola , where one pregnancy immediately follows another. 22 In all species the mammary gland fills the axilla and extends well on to‐the back over m. serratus magnus. The nipples are thoranic in position and lie towards the median border of the gland.