Fishery Brxird for Scotland. 



While in some fii^hes both the testis and tlie ovaiy may be found 

 developing, in others only the testis or the ovary is developing. In 

 the latter case the portion of the organ belonging to the other sex 

 may be so small that it may escape notice ; but, so far as my experience 

 goes, it is present. All are potentidl /ifrmaphrodiies, but only a 

 proportion are functional hermai)hroditef. 



The fishes have been arranged in the table in the following classes : — 

 (1) predominant males, (2) predominant females, and (3) sexes equal. 

 The predominant male or female indicates that the testis or the ovary 

 is large, while the organ of the opposite sex is very small. The 

 nu7nber examined during each month, with their range of length, is 

 given. The length of the fish is the distance from the anterior tip of 

 the snout to the extremity of the longer tail ramus. 



The range in size of the ova found in the fishes is entered in the 

 last column. 



A number of the fishes were spents. 



The fishes entered opposite each month do not all belong to the 

 same year. The observations were carried on over a period of three 

 and a half years. 



*The sizes gi\en include all the samples from all the irroups that were measured during the month. 

 Sample eggs from every ovary were not measured. But the ovaries were examined for any indication 

 of ripening ; it is not therefore likely that in any of the fishes there were eggs of greater diameter than 

 •45 mtn. 



Out of 404 fishes, 88, measuring from 31 to 40 cm., had the sexes 

 equal, while 128 predominant males measured from 31 to 50 cm., and 

 238 predominant females measured from 32 to 49 cm. It may be 

 noted that the fishes having the sexes equal did not appear among the 

 specially large individuals. 



A number of reproductive organs were obtained from a collection 

 of fishes captured ofi" the west coast of Orkney in January. 



The hermaphrodite condition is indicated when a testis and 

 an ovaiy are combined in one organ. They may be of equal 

 size, as, for example, in Fig. 21, or the testis or the ovary may be much 

 the larger, as, for example, in Figs. 3a and 19 respectively. In the 

 latter division the very small sexual organ seems to be quite normal, 

 and is, I consider, functional. These are the conditions where the 

 sexual organs are not specially large, i.e., in small bream {e.g., Figs. 

 3a, 9, 19, 38, which are of natural size). But when one sex pre- 



