in some Chatopod Annelids. 327 



to what Steenstrup had supposed from the analogy of marine 

 worms, there is no relation to metagenesis in the phenomena of 

 budding in this Naid ; for he had never seen generative organs 

 in the separated buds. He had, however, never been able to 

 keep these buds long alive. He also had seen (p. 304) sexual 

 organs in the parent while budding, though he had never seen 

 well-developed sperm and ripe eggs present during this process. 



The phenomena of fission in Stylaria longiseta, so far as I have 

 observed them, confirm the statements of Miiller and Schultze 

 in substance ; for there is nearly always a passage over of one 

 iparental ring to each bud ; and since fission takes place, as I 

 have seen, while the parent has eggs and sperm, and I have 

 never seen the fullest development of the latter in the buds, I 

 cannot believe that there is any such metagenetic relation in 

 this process as has been observed in Syllis and allied genera. 



In Nais rivulosa, however, the facts are somewhat different ; 

 for in several continued observations of individual Naids, ex- 

 tending in one case over twelve weeks, I have known but once 

 or twice of a passage of the parental rings into the bud ; while, 

 after an elongation of the parent body, I have very uniformly 

 seen fission recommence in the point at which buds were given 

 off before, or at some point posterior to it, and once anterior ; 

 and finally, although I have seen fission taking place between 

 each of the rings from the 15th to the 22nd, I have not been 

 able to discover that it does so in any order. But here, as in 

 Stylaria longiseta, I have found no metagenesis in the fission. 



The facts obtained in regard to fission in Dero limosa are un- 

 fortunately meagre, the comparative slowness of the merismatic 

 function making the only two series of observations carried out 

 proportionately unfruitful. In none, however, of the succeeding 

 lauds, from Aug. 15th to Oct. 10th, was there any carrying off 

 of parental segments by the separating parts, nor was there 

 anything like metagenesis observed. 



My observations upon Enchytrceus triventralopectinatus are 

 similarly scanty, but are just sufficient to confirm and extend 

 the facts observed in the two other short-lipped Naids. In all 

 the cases observed, the separation was of a part wholly new- 

 formed, without inclusion of the older segments of the parental 

 body. 



It is evident, from the above facts, that in Stylaria longiseta, 

 as Miiller and Schultze have shown is the case in S. proboscidea, 

 the point of fission moves regularly forward, ring by ring, and 

 more commonly, in the former Naid, from the 16th to the 12th 

 pairs of hook combs, though the extremes between which I have 

 known it to occur are the 17th and 10th (to judge from 

 Miiller*8 account, it occurs further back in the latter Naid); 



