BY W. R. COLLEDGE. 79 



In the last segment in a central cavity lie three organs, 

 fig. 32. Two are alike round, and the third, slightly larger, is 

 oval. They are of a very dark brown colour, have a short neck 

 like a flask, from which a tube several times their length pro- 

 ceeds into the preceding segment ; the latter contains a dense 

 glutinous material which resists the action of most aniline dyes. 

 In thoce species which form their eggs into rafts, it is believed 

 to be the material which cements them together ; but as the 

 Scots Gray lays its eggs separately, it is not required for that 

 purpose, but it may form a protective varnish for them. The 

 former organs are the spermathecce, and in one of them I found 

 male spermatozoa. These are like fine hairs tapering to a point 

 at the tail, while the head portion is a little blunter, but with no 

 sensible mark of division at the neck. 



