119 



about midway between the moiuli and tlie loot and abuts 

 on tke liver lobules at this point. It is rather flattened 

 here, but from a point immediately below the foot it 

 contracts considerably from side to side and becomes 

 deeper. The deepest part is where the male abuts against 

 the ovigerous portion, and the organ gradually tapers to 

 a rounded point. Midway between this free end and the 

 parieto-splanchnic ganglion it is attached to the adductor 

 by the connective tissue that covers the under surface of 

 the muscle and the adjacent organs of Bojanus. The 

 whole of this mass is not gonad, for, as described above, 

 part of the alimentary canal courses through it (fig. 1, 

 Al. c. 3, Al. c. 4), and is thus surrounded by the sexual 

 organs; but the intestine does not penetrate to the 

 ovigerous part in P. ojjercularis, whereas in P. inaxinius 

 it runs almost to the end of the mass. 



The ovigerous part occupies the hinder end, and can 

 be easily distinguished from the male part when the 

 products are ripe, for it has a beautiful vermilion-pink 

 colour, becoming deeper as the eggs approach matvirity. 

 During the ripening of the products, the male part 

 becomes cream coloured, and the junction of the cream 

 and red is quite sharp though irregular in outline, and 

 there may be islands of ovigerous tissue surrounded 

 completely by the male organ, or the female part may 

 extend a considerable way forwards into the centre of the 

 seminal portion which then lies on the exterior. After 

 discharge of the contents, or when collected before the 

 products have developed, the organ has a shrunken and 

 flabby appearance, and is of a yellowish-brown colour, 

 and the intestine may be seen through it. 



The male and female products of the one individual 

 do not appear to be ripe at quite the same time, though 

 there cannot be much difierence in this respect. FuUarton 



