AMPHITBITE. 233 



functions of the branchiae, physical and mechanical, may be combined in 

 some manner unknown, notwithstanding the apparent design of Nature 

 be frustrated in regard to the latter. 



It would be a problem of infinite curiosity and interest, investigat- 

 ing the precise extent of the evolution of such a complication of organs 

 as may subsist throughout the body. What are the spots, where are 

 the intervals by which they will be afforded ? Do their elements reside 

 in each of the segments, or are they dispersed among a certain number of 

 segments ? Can we obtain the materials allowing conjecture that many 

 germs are ready to unfold similar generations when opportunity offers ? 



If the important privilege of reproducing what the animal employs 

 for its own preservation subsists in many parts below, should we not infer 

 that there may be some unknown means whereby a new tube can be con- 

 structed, in order that the regeneration shall serve its original purpose ? 



After divulsion from the original site, the Amphitrite commonly 

 fixes the extremity speedily again. But a fortnight elapsed before ad- 

 hesion of that of the preceding specimen, mutilated of the fragment, 

 possibly because the secretory organs had been lost along with it. In 

 five weeks a slight sheath extended from the end of the tube along the 

 glass. Its source may be probably sought in two terminal organs, doubt- 

 less glandular below, besides which there must be much secretion from 

 the rest of the body. Figs. 10, 11, b. 



During reproduction of an adult Amphitrite preserving its natural 

 place, the disproportion between the renovating parts and the body is 

 always diminishing ; that is, the dimensions of the body and the plume 

 are approaching their mutual relation. But if there be no fallacy the 

 reverse succeeds with a fragment. Here the disproportion is continually 

 augmenting inversely. The body pines as the plume enlarges. The just 

 proportion of a fine adult specimen in situ may be rated at the fourth of 

 the length of the body, three inches, for example, if the latter be twelve. 

 If half its length, the plume would be thought monstrous. But a new 

 plume, generated from a fragment of the extremity, may become double 

 the length of the body. The one pines as the other grows. Perhaps 

 evolution of the lower parts of the animal depends chiefly on the func- 



2o 



