PHYLUM ANNELIDA. SEGMENTED WORMS 



187 



Aufolyius, a Polychaete reproducing by budding at the posterior end. 



Aeolosoma, a fresh-water oligochaete reproducing by transverse division. 



Figure 101. Asexual reproduction in annelids. Top, a marine polychaete budding at the posterior 

 end. Bottom, a fresh-water oligochaete showing a budding segment. (After Mensch.) 



the missionaries because it was eaten by the 

 natives; also because it appeared periodically 

 in certain localities in enormous numbers for 

 only a few hours. It makes its appearance 

 (swarms) almost invariably in the months 

 of October and November, and usually at 

 the time of the third quarter of the moon. 

 Other important factors, such as the velocity 

 of the wind and the stage of sexual matur- 

 ity, may account for a departure from this 

 time to produce lesser swarms at other moon 

 phases during these two months. The pos- 



terior half of the worm breaks off from the 

 parent worm and swims to the surface. The 

 enclosed eggs and sperms are shed into the 

 sea in the early morning, and in some local- 

 ities in such enormous numbers that the 

 surface of the sea has been likened to a 

 thick noodle soup. The eggs develop into 

 young larvae rapidly, and in three days sink 

 to the bottom. Other palolo worms occur in 

 different parts of the world, particularly in 

 warm seas. The Atlantic palolo swarms in 

 June and July. 



&:iiM^^^r0: tAa\e v/ith sexual 

 y^^;^v;;j;^v region detached 



Mature 

 fema 



Sexual segments sv/im 

 to surface; eggs and 

 sperms are discharged 



Parent worm 

 regenerating 

 sexual region 



Sexual reproduction of the palolo worm, 

 Eunice, a polychaete 



Figure 102. The Pacific palolo worm, Eunice viridis, has its burrows in coral reefs; it pro- 

 duces many posterior segments filled with eggs or sperms which are periodically cast off. 



