A STUDY OF METAMERISM. 



421 



figs. 75 — 78. In fig. 75, a, b, is drawn a compound metamere ; 

 in fig. 76, A, B, a spiral of category vii ; in fig. 77 a spiral of 

 category viii ; and in fig. 78 a longer spiral of category x. 



A number of adult worms was examined, and the following 

 table shows the number of metameres in them. Mature worms 

 were chosen as far as possible. 



It will be seen, if we may judge by the figures given, that 

 few, if any, new segments are added to the worm after it leaves 

 the capsule. 



Another count of 25 worms gave the following figures : — 

 99, 89, 85, 100, 90, 96, 95, 95, 97, 101, 101, 105, 101, 106, 

 88, 84, 88, 95, 100, 92, 100, 91, 105, 92, 96. These numbers 

 give an average of 99*6. If we combine this with the average 

 of the 15 cases given above (94*4) we get 97 for the average 

 number of segments of 40 worms. 



V. Abnormalities at the Posterior End. 



In one lot of 525 worms 40 were found showing newly 

 formed posterior ends due to regeneration. 

 In these 40 worms we find — 



