182 



THE EVOLUTION OF SEX. 



In the higher bristle-footed worm-type (Chcrtopoda), asexual multiplication 

 occurs in great variety of expression. Some, when alarmed, break up in a 

 panic, but a few are also known to do this in apparently normal life. Each 

 part — there may be more than two — reproduces the whole. Thus, at a com- 

 paratively high level among animals, reproduction may be literally rupture. 



Fig. 58. Syllis ranwsa, a ringed marine worm, in which asexual multiplication has produced 



a branched appearance. — From M'lntosh, "Challenger" Rep. on Annelida. 



Oftener, however, budding precedes the division, and curious chains of ringed 

 worms are thus produced. Nor do the budded individuals always keep in a 

 straight line, but, as in the freshwater naids, may abut at angles, and form a quaint 

 living branch. To what degrees this irregularity of budding may attain is well 

 seen in the accompanying cut of a portion of a worm {Syllis ramosa) found 



Fig. 59. — Comet form of a Starfish, showing how one arm "regenerates" or 

 reproduces other four. From Cams Sterne, after Haeckel. 



on the " Challenger " voyage. The buds occur laterally, terminally, or on any 

 broken surface, and the result is an almost bush-like compound organism 

 rivalling even the hydroids in the freedom of its branching. Some of the 

 branches becomes males or females, and go separate, or are sent adrift. In 



