'I'HE ANATOJIV OF ONCHOLAIMIIS VULGARIS, BAST. 141 



a finely granular substance which staius intensely — almost 

 black — with hajmatoxylin. 



A fine canal {can.), 0"0075 mm. in diameter, traverses the 

 entire length of the cell, and becomes continuous with the 

 duct. Its course is in places slightly tortuous. It receives 

 numerous smaller canaliculi which traverse the protoplasm. 

 Its walls are also composed of condensed protoplasm; its 

 contents when fixed are very finely granular and acidophil. 



The short duct (PI. 8, fig. 33) runs from the anterior pole 

 of the cell to the niidventral line, and in the substance of this 

 line to the external aperture. Its wall is composed of pro- 

 toplasm continuous with the protoplasm of the cell ; one or 

 two small nuclei occur in it. There is a very fine cuticular 

 lining continuous with the external cuticle. 



Haniann describes a similar organ in the embryos found 

 in Zeus faber. It again consists of a single cell, in 

 front thread-likcj at its greatest breadth extending from one 

 lateral line to the other, is always in connection with the 

 dorsal median line, contains a canal lined by a " glashelles 

 membran," which opens dorsally behind the lips. [The italics 

 are mine.] 



Cells occur in the body cavity identical with the basophil 

 cells of Oncholaimus vulgaris. 



Lying between the ventral gland and the right lateral line 

 is a solid cellular mass, possibly the rudiments of the gonads. 



COMPAEATIVE MORPHOLOGY OF THE ExCRETORY GlANDS IN 



Nematodes. 



This subject has been very fully worked up by Jagerskiold 

 in a masterly paper (9). I have, however, a few points 

 to add. I shall commence with a brief summary of his 

 results. 



He finds that the excretory organs of Nematodes can be 

 classified into four groups : 



(1) The ventral gland of the most free living forms (PI. 9, 

 fig. 35). 



