No. 2.] STOLONIZATION IN AUTOLYTUS VARIANS. 277 



of the anterior lateral tentacle, which becomes evident soon 

 after the tentacle has made its appearance. 



The male and female chains of Autolytus varians also show 

 another difference very similar to that observed by Malaquin 

 (9), de St. -Joseph {7), and Pruvot (8), in other chain-forming 

 species, viz. : the male chain is always longer and contains 

 the greater number of stolons. Few female chains of this 

 species are found with more than four or five stolons, while 

 male chains may have as many as eight stolons. 



The relative number of male chains appears also to be greater 

 than that of the female chains. This fact is particularly evi- 

 dent among the free individuals, where five or six males may be 

 found to a single female. 



External Phenomena of Stolonization as Represented 

 IN THE Chain of Stolons. 



The successive stages in the development of stolons of 

 a chain are well shown in a male chain, as is represented in 

 PI. XIII, Fig. 6. This chain consists of six well-defined stolons, 

 with a distinct embryonic region (r.^.), and is attached to the 

 thirty-fifth segment of the parent stock. Externally the thirty- 

 fifth segment, which is in this specimen the segment of prolif- 

 eration, presents no characters different from those of the 

 preceding setigerous segments. 



The embryonic region of this specimen consists of five seg- 

 ments, the two anterior of which are of equal size, and, being 

 the youngest segments of the series, may be regarded as typi- 

 cal embryonic segments. These two segments are very much 

 smaller than the segments of the parent stock and show no 

 signs of parapodia. The third, fourth, and fifth segments are 

 slightly more advanced and present on each side small papilla 

 which represent rudimentary parapodia. These segments are 

 of equal size and differ sufficiently from the two segments pre- 

 ceding them and the series following to be regarded as having 

 been formed in close succession and as developing at an equal 

 rate toward the formation of a new stolon (St. A). Very fre- 

 quently instead of three equally developed segments, as repre- 



