INTEA-OVARIAN EGG OP SOME OSSEOUS FISHES. 53 



On the Intra-Ovarian Egg of Some Osseous 

 Pishes. 



By 

 Robert Scharflf, Ph.D., B.Sc. 



With Plate V. 



The following researches were carried out during the past 

 summer while acting as assistant to Professor Mcintosh, at 

 the St. Andrew's Marine Laboratory. The fresh material for 

 the investigations was taken from St. Andrew's Bay, which is 

 extremely rich in all kinds of animal life. Professor Mcintosh 

 kindly placed at my disposal many preserved ovaries and ova 

 from his large collection, which served me for sections. But 

 my contributions to the history of development leave a good 

 many gaps to be filled up by future observers, as J was not 

 able to obtain a consecutive series of the ovaries of any species. 

 If an ovary be opened it is generally found to contain eggs of a 

 certain size only, and in order to get an entire succession of 

 the various stages, ovaries of the same species should be pro- 

 cured at different seasons of the year. It is not possible to 

 see all the phases of development in one and the same ovary. 

 There is one form, however, which abounds near St. Andrews, 

 and which, due to its spawning period being spread over 

 several months, contains ova of almost all sizes. This is the 

 gurnard (Trigla gurnard us). It is in many other points a 

 very suitable object for investigation. 



The following is a list of the species of fishes whose ova or 

 ovaries I examined : — Trigla gurnardus, G-adus virens, 

 G. seglefinus, G. luscus, G. merlangus, Lophius 



