DOKSIBRANCHIATE ANNELIDANS. 



245 



contained fluid, that the division of the body of the parent animal takes 



place. In each fragment is 

 therefore incubated a consi- 

 derable number of ova. Filled 

 still by the fluid of the peri- 

 toneal cavity, each fragment 

 becomes subservient to the 

 end of hatching the young. 

 It resists decomposition only 

 during the period required for 

 the accomplishment of this 

 purpose. When the ova are 

 committed to the sand, the 

 fragment rapidly disappears 

 by putrefaction. The fissure 

 of the body, thus interpreted, 

 becomes the last act of the 

 parental worm, since the por- 

 tions into which the body is 

 subdivided by fissure never 

 take food. With the fissure 

 the necessity for food termi- 

 nates. If, on the contrary, 

 the division of the body were 

 the first step of a real re- 

 productive operation, charac- 

 terized by the superaddition 

 of new segments to the body, 

 each fragment should grow 

 voracious and consume extra 

 supplies of nourishment in 

 order to provide the necessary 

 pabulum for the reparation 

 of mutilated parts. As this 

 is not the fact, the inference 

 is clear that the division of 

 the body is not the prelude 

 to a series of reconstructive 

 operations by which parts are 

 made "wholes," or mutilations 

 repaired. 



(642.) DORSIBRANCHIATA. - 



In the second order of the 

 Annelidans the respiratory 

 apparatus consists of nume- 



Fig. 



"sLUrf: 



Laodicoa antennatn. 



