vi PRACTICAL DIRECTIONS 357 



minute cauliflower : look for the spermiducts (partly 

 imbedded in the body-wall) in connection with the funnels, 

 and for the two pairs of spermaries, each projecting back- 

 wards from the septum in front of the corresponding 

 seminal funnel. In Lumbricus the spermaries and funnels 

 are enclosed within the median sperm-reservoirs (p. 355), 

 which must be cut open' and washed out in order to see them 

 (compare Figs. 82 and 86). Remove and examine an 

 ovary, a spermary, and a seminal funnel. 



IV. Remove the sperm-sacs carefully, and make out 

 further details as regards the enteric canal (see IT. 2). 

 Note the cesophcigeal pouches and glands. Cut open part of 

 the intestine along one side, and observe the thick dorsal 

 fold or typhlosole projecting into it. Sketch. 



V. i. Note the small cerebral ganglia or brain on the 

 dorsal side of the buccal sac, and then cut through the an- 

 terior part of the pharynx just behind the brain. Carefully 

 remove the enteric canal, noting as you do so the ventral 

 sub-intestinal blood-vessel. The -nervous syste>n will now be 

 exposed. Observe again the paired cerebral ganglia, from 

 which arise a pair of connectives, forming a small nerve-ring 

 or collar around the buccal sac, and continuous ventrally 

 with the ventral nerve-cord, consisting of fused lateral halves 

 and extending along the whole length of the ventral body- 

 wall, passing through a perforation in each septum, and 

 expanding slightly in each segment, so as to form ganglionic 

 swellings. Three pairs of nerves 'are given off in each seg- 

 ment. Sketch. 



2. Remove the nerve-ring and a small portion of the 

 ventral cord, and examine with the low power. Sketch. 



3. A lateral neural vessel can be seen close to the ventral 

 cord on either side. Remove a portion of the cord, and note 



the sub-neural vessel. 



VI. Further details as regards the nephridia and generative 

 organs (see above) are best made out in a worm which has 

 been preserved in spirit. Very carefully cut away the enteric 

 canal from the gullet backwards so as riot to injure the septa 

 more than necessary ; the nephrostomes can then be seen 

 with a lens, looking like small, whitish clots. Remove an 

 entire nephridium carefully as before ( II. 4), stain, and 

 mount in glycerine or balsam. Note the three loops, and 

 a. the ciliated nephrostome ; b. the first, slender part of the 

 tube with its cilia ; c. the second, wider, ciliated part ; 

 d. the third, still wider, glandular part ; and e. the fourth, 



