ON BUDDING IN ANIMALS. 11 



In the group of Polychaets budding attains even greater 

 prominence than in the foregoing, yet out of the thirty-seven 

 families comprising the order it occurs only in two, viz. the 

 Syllida? and the Serpulidse, and, as mentioned, the species are 

 small.* 



Since the days of 0. F. Miiller the formation of linear buds 

 has been known in Autolytus prolifer (his Nereis prolifera), the 

 Danish author having noticed a chain of three individuals, the 

 youngest the most anterior, and observed that those which 

 separated from their parent were filled with eggs. In the family 

 of the Syllidce, to which this species belongs, the most remark- 

 able examples of budding occur. These have been described by 

 many authors, some of whom, as, for instance, De Quatrefages, 

 have termed the process one of alternation of generations. In 

 essential particulars this consists in these Annelids of the bud- 

 ding from a nurse-stock of male and female buds, each differing 

 from the other in external form. A series of gradations, indeed, 

 may be observed from the condition in Haplosyllis, in which the 

 posterior end is thrown off after the eggs or other elements in it 

 are matured, to that in Autolytus prolifer and Myrianida, in 

 which one or more buds, either male or female, form a chain at 

 the posterior end of the nurse-stock. 



In Myrianida the bud takes its origin in the segment (called 

 by Malaquinf the formative zone) in front of the tail (pygidium). 

 It is considerably narrower than the adult, and that next the 

 latter is the youngest, several segments without feet, however, 

 being in front of it. While pigment-touches are present in the 

 youngest, there is no head, and thus Malaquin considers that 

 the anterior extremity is subsequently formed, or, as he terms 

 it, is a new stolon. Proceeding backward, the number of 

 segments in the buds increases, and the parts attain greater 

 complexity. Little thickenings — after the head is formed — in- 

 dicate the tentacles, the median cylindrical, the lateral somewhat 

 flattened. In the male the latter is a compound structure, 

 according to Malaquin, the result of the fusion of the lateral 

 (anterior) tentacles and the palpus, the outer limb of the bifid 

 organ corresponding to the former, the inner to the latter. In 



:;; Eyes have been found in a segment of Eulalia by Verrill. 

 f ' Recherches sur les Syllidiens,' Lille, 1893. 



