O. G. Dely szerk.: Vertebrata Hungarica 15. (Budapest, 1974)

Topál, Gy.: Field Observation on Oriental Bats. Sex Ratio and reproduction 83-94. o.

range. At present we would need exact and detailed observations on the reproductive cycles of the individuals. Pipistrellus ceylonicus (KELAART, 1852) From the population at Lonavla(5) both sexes - 1 male and 1 female-were collected on July 16. InKarlaCaves(7) on the same day I found 2 males and 4 females, however, the males seemed to hide one by one in smaller cracks and holes. The females found in Lonavla(5) and in the Karla Caves

(7) were in sexual rest on July 16. Actually, I did not study the possible early stage of pregnancy or sperm storage. Pipistrellus dormeri (DOBSON, 1875) The only colony studied consisted of 1 male and 7 females in Jabalpur(14) on March 20. The uteri of the females from Jabalpur(l4) were reddish and swollen, probably showing an early stage of pregnancy on March 20. Scotomanes ornatus (BLYTH, 1851) A female caught in Cue phuong(33) had signs of former pregnancy in the right horn of uterus on May 9. Probably the reabsorption of the half-grown or even younger fetus occured as I found only remains of placenta in the uterus

. Scotophilus kuhlii LEACH. 1822) In a group of this species 17 males and only 1 female were collected in Calcutta(22) on February 6. The scattered specimens of this species were aU single males or small groups of males in Hanoi(36) and Xuan dinh(31), and 1 female was together with 2 males in Co loa

(37 ) during April. At the same time the pregnant females gathered in separate and greater groups; though the males were to be found at a small distance from the females. The only female I collected in India was with swoUen uterus and presumably showed the early marks of gravidity. This was observed in Calcutta(22) on February 6. In Vietnam I studied this species often and succeeded in getting some data on its reproductive cycle. In Co loa

(37) I caught a female in the company of males on April 16. It was not gravid though all the 7 females collected in Hanoi

(36) were with fetuses both in the right and left horns of uterus in April. Thegreatest length of the embryos varied 11 to 15 mm. on April 15, from 11 to 17mm. on April 26, and from 17 to 20 mm. on April 29. I think this data show that the birth time of this species probably begins earlier in Vietnam than GOPALAKRISHNA (1949) has observed it in South India. Scotophilus heathi (HORSFIELD, 1831) All the 3 females discovered were pregnant in a hiding place at Thanh liet(32) on April 22. There were no males. One female collected by me in the Elephanta Caves

(3) had no signs of sexual activity on October 30. In one of the Thanh liet(32) females I found a ringt and a left side embryo with a maximum lenght of 17 mm.

, while in the other 2 only one embryo was present in