361 



The occurrence of polyovular follicles, that is Graafian follicles 

 that contain two or more ova instead of only one, has been recorded 

 in various species of Eutheria by different authors bat apparently 

 has not been met with before in the Marsupialia. 



It has been recorded in human beings by Schottländer (18\ 

 Nagel (14), Stoeckel (23) and Rabl (16); in bats by van Bexeden 

 (4); in cats by Rabl (16) and Schrön (19); in dogs by P. and M. 

 Bouix (7) and WactEner (27); and in rabbits by Wagener (27) and 

 HoNORE (8). An interesting case has been recorded by Smyth (20 a) 

 in the dog which suggests that this abnormality may be hereditary. 

 A Bitch had fourteen pups in a single litter, one of which was spaed 

 and on examining the ovaries it was found that they contained nearly 

 ripe follicles many of which had two or three ova. Another of the 

 pups was examined and the ovaries were found to possess follicles 

 with two, three and in one case even seven ovules. Yet another of 

 the pups had a litter of nine at the first birth. 



In the majority of the above cases however the follicles were 

 very young and only in two of them, i. e., Schrön and Honore were 

 there cavities containing liquor folliculi in the membrana granulosa. 

 Those described here however are in all stages of development from 

 primordial follicles up to follicles that are quite ripe. 



The frequency with which this phenomenon occurs appears to 

 vary greatly in different species thus van Beneden states that in one 

 bat (Yespertilio murinus) although a large number of ovaries were 

 examined no example of it was found whereas in the horse-shoe bat 

 (Rhinolophus ferrum-equinum), he says that it was met with in a 

 large number of cases. Again Schrön records that he encountered 

 it only twice in the ovaries of 400 cats and once in 80 dogs. It is 

 apparently more frequent than this in D. viverrinus for it was disco- 

 vered twice in forty-five animals. 



Specimen A. 

 In this first example of D. viverrinus both the ovaries had been 

 sectioned and mounted by Professor Hill. They are in a very good 

 state of preservation, and as the animal from which they were taken 

 had been in heat some days they contain ripe follicles. The majority 

 of the follicles are quite normal and it is only a small proportion of 

 them that contain more than one ovum, but these are to be met with 

 in all stages of development. In more than twenty ripe follicles only 



