162 WILLIAM WALLACE. 



The ovary of this species is of especial interest owing to 

 the fact that it functions during about five months of every 

 year of the adult animal's life as a uterus. lu only one 

 other "British" Teleostean, viz. Sebastes marinus, the 

 Norway haddock, does a gestation of the young take place. 

 The latter species is obtained by trawlers in rather deep 

 water in the northern portion of the North Sea. Zoarces, 

 on the other hand, is essentially a shore fish, commonly 

 found in tidal pools, and apparently not going much beyond 

 the laminarian region at any time. These two British vivi- 

 parous fishes are not at all closely related. Sebastes is a 

 Scorpsenoid, whereas Zoarces, while usually regarded as a 

 blenny (vivipai'ous blenny), has recently been relegated by 

 Gill to the Anacanthine family, the Lycodida?, and is clas- 

 sified accordingly in 'The Scandinavian Fishes' (1893). 



The ovary of Zoarces is a single oval bag suspended by 

 the mesovarium to the dorsal wall of the abdominal cavity. 

 In the " resting " condition the organ is confined to the 

 hinder third or so of this cavity. The oviduct is very short, 

 and opens, in the adult, just behind the anus. When full of 

 young the ovary extends forward in and almost fills the 

 body-cavity, greatly distending the abdomen. The number 

 of young of one gestation varies, generally speaking, from 

 two or three to over a hundred,^ in correspondence with the 

 size and age of the mother. Although some amount of 

 variation, local and individual, in the breeding season seems 

 to obtain in Zoarces, there can be no doubt that the species 

 as a whole breeds only once in the year, and bears its young 

 in the depth of winter, as Willoughby observed.- The eggs 

 are fertilised in August or September, and the young are born 

 during the months of December, January, and February. 

 At birth the young fishes are about 5 cm. or two inches long, 

 and in general resemble the parent. 



' Four hundred (Stulilmaiui, 1887). 



' See on tins point Bainbcke (1888), 'The Scandinavian Fibhes,' part ii, 

 p. 606; Mcintosh and Masternian (1897), p. '218; ' Couch's Fishes,' vol. ii, 

 p. 240, 



