398 



TRICOMA AND OTHER NEW NEMATODE GENERA, 



two ventially submedian hairs situated opposite each other just in 

 front of the anus. A row of from fourteen to twenty ventral 

 accessory sexual orgaus, occupying a space twice as long as the tail, 

 occur in Iront of the anus. The distance between any two adjacent 

 components of this series of organs gradually increases anteriorly, 

 as does the size of the organs. As to the structure and function 

 of these organs, I have been able to form satisfactory conclusions. 

 I have already pointed out the existence in the male oi Monhystera 



mas-paiKillatus of a ventral 

 row of minute unicellular 

 glands, and also the exist- 

 ence in the male of Dory- 

 laimus Lartgii of a ventral 

 row of innervated papillse. 

 In my little Chromadora, 

 however, I have clearly 

 seen that each of these 

 ventral accessory organs is 

 supplied with both a nerve 

 and a unicellular gland. 

 The nature and position 

 of the details will be best 

 understood by consulting 

 the figures. One now 

 sees clearly how these 

 accessory organs may 

 serve the male during 

 copulation. The sensitive 

 nerve-end coming in contact with the female acts either in a reflex 

 manner on the gland, or through the voluntary nervous system, and 

 causes it to pour out its secretion. Concerning the function of the 

 secretion, we must judge from other genera, such as Bhahditis, where 

 the male is known to cement himself firmly to the female during 

 copulation. We may therefore suppose the secretion of the glands 

 to serve also in Chromadora the function of cementing the male 

 to his mate, although, so far as I know, the act of copulation has 



Fig. 6.— I, male of Chro- 

 madora minor. II, one of 

 the ventral accessory organs 

 of the same worm. Ill and 



IV, head and anal region of 

 the same worm. 



a, pharynx. 



b, eye-spots. 



c, oesophagus. 



d, h, ventral accessory organ. 



e, nerve-ring. 



/, excretorj' pore. 



g, gland of accessory organ. 



i, ventral gland. 



j, organ of unknown nature. 



k, blind end of testicle. 



I, cephalic seta. 



m, ribs of pharyngeal open- 

 ing. 



71, papilla. 



0, dorsal tooth. 



p, pharynx. 



q, stria. 



r, sub- cephalic seta. 



s, dorsal eye-spot. 



t, intestine. 



u, one of the ventral male 

 accessory organs. 



V, ejaculatory duct. 



IV, one of the accessory 



organs. 

 X, anus. 



y, left spiculum. 

 z, accessory piece. 



