16 TEE ZOOLOGIST. 



The advantages of budding in these small Polychsets, such as 

 Autolytus, appear to be the wide diffusion of the species, since 

 the buds of both sexes and the females bearing the ovisacs are 

 extremely active swimmers, and thus before the larvae are ready 

 for a free life they have been borne great distances. In our 

 country it is in the colder months of the year, viz. from February 

 to April, that they most abound in the ocean, a period less 

 prolific in the larvae of the Polychsets generally than the warmer 

 months, though mature adults are not uncommon. What are 

 the reasons which, with few exceptions, confine this mode of 

 increase to the family of the Syllidce ? The question is difficult 

 to answer. It is true the parent- or nurse-stocks are more or 

 less sedentary, but they share this habit in common with many 

 others which have only the ordinary method of increase, or 

 which throw off only the posterior end with the eggs. The 

 Syllidce, however, are forms almost universally distributed, and 

 in considerable abundance, from the Arctic to the Antarctic 

 Ocean. The common species and its buds are often met with 

 in the Arctic Seas, and the same remark applies to Filigrana. 

 An interesting feature— specially dwelt on by Malaquin — is the 

 gradual transition from forms with no further differentiation 

 than the collection of the eggs and other elements in the pos- 

 terior part of the body — which has swimming-bristles — to those 

 in which this region presents several more or less mature and 

 individualised buds. Nature thus truly does not advance by 

 leaps. Moreover, while some of the family produce young 

 directly from eggs, others increase only by buds. On the whole, 

 it would seem that such Annelids have an organization so 

 plastic as to render budding easy, and that in such forms as 

 Autolytus and Myrianida it has been found highly advantageous 

 in the struggle for existence. After all, there is nothing more 

 wonderful in the soft tissues of a segment developing eyes, 

 sense-organs, and other parts than their formation in the egg 

 itself. 



When we come to the Polyzoa, budding is everywhere a 

 general feature, from the few in Loxosoma, which separate from 

 the parent, to the arborescent polyzoaria of the marine and 

 fresh-water Polyzoa, in both of which the new buds remain in 

 connection with the old, and constitute complete colonies. In 



