OVARIES IN TELEOSTEAN AND ELASMOBRANCH FISHES. 165 



increase in size towards the inside of the ovarian wall. On 

 account of the great development of these spaces the 

 muscular coat is only attached by occasional strands to a 

 relatively thin layer of stroma, containing venous blood- 

 vessels and developing ova, that underlies the germinal 

 epithelium. 



(h) On the Reproduction of Zoarces viviparus. 



There are given below, in tabular form, some particulars 

 as to the rate of growth, age at first maturity, numbers of 

 progeny, and relative numbers and size of the sexes of this 

 species. 



From Table I it is evident that at least some individuals 

 attain sexual maturity at the end of their second year, dating 

 from hatching (September). 



Table I. 



' Age calculated from September, when most of the larvae are hatched. 



