46 MUSSEL CULTURE 



alike. Towards the spawning season the sex of 

 a mussel can be told at a glance, without much 

 difficulty, by a difference of colour which usually 

 appears. The male exhibits a whitish or reddish 

 yellow, while the female is a deep red or orange- 

 red colour. The genital duct can frequently be 

 traced crossing the brown - coloured organ of 

 Bojanus. 



Sabatier seems to have studied the mussel when 

 the reproductive organs were inactive, but Lacaze- 

 Duthiers notices the difference of colour, as also 

 does Purdie in the New Zealand mussel, while 

 Wilson ^ states that, after a close inspection, it 

 will be noticed that the sperm sacs are mostly 

 arranged ' in more prominent groups than the 

 ovigerous masses.' This author also describes the 

 genital products as follows : — The male sperms or 

 spermatozoa ' have a balloon-shaped head tapering 

 continuously off to a fine tail' When taken in 

 the perfectly ripe condition, by cutting open the 

 mantle of the parent they form a creamy fluid. If 

 the sperms, when highly magnified, are entirely 

 free from one another, and active in their move- 

 ments, they are perfectly ripe. If on the other 



^ Fotirth Ajt72ual Report of tin Fishery Board for Scotland^ 

 Appendix F, 1886, p. 219. 



