No. 2.] STOLONIZATION IN AUTOLYTUS VARIANS. 273 



Attached to the last segment of the parent stock in mature 

 individuals may be found a chain of stolons (PI. XIII, Figs, i 

 and 6) in different stages of development. Of these stolons 

 the posterior is the oldest and most matured individual ; the 

 one next to it being somewhat younger and less mature, and 

 the ones anterior to this being progressively younger and less 

 mature, so that the most anterior presents only very faintly the 

 outline of a stolon. The number of such stolons in a single 

 chain may vary from several to as many as eight, and appears 

 to be dependent upon the size of the parent stock and the sex 

 of the stolons. In a larger chain, where the number of stolons 

 may be as many as seven or eight, the different stages of devel- 

 opment are progressively represented in each successive stolon. 

 In a chain of fewer stolons, however, this is not so marked, 

 and more frequently chains composed of but several stolons 

 are found in which an almost mature posterior stolon may be 

 attached to a very young and immature anterior stolon. Fre- 

 quently specimens of this species may also be found which 

 contain but a single, often quite mature, stolon, and give no 

 evidence of a chain formation. Such specimens are usually 

 smaller and younger in appearance and seem to indicate the 

 very beginning of the process of stolonization. 



Anterior to the youngest stolon and forming the connective 

 between the chain of stolons and the parent stock are a number 

 of segments (PI. XIII, Fig. 6, r.e) which are still younger and 

 give little evidence of belonging to a distinct stolon. This 

 region, since it is composed of the youngest and least devel- 

 oped segments, I shall designate as the embryonic region. The 

 segments of this region are successively produced as outgrowths 

 from the last segment of the parent stock, which segment, 

 since it presents internal structures relative to this outgrowth 

 that are different from those of the preceding segments, I shall 

 refer to as the segment of proliferation. 



Description of the Free Stolons. 



Before proceeding to trace the external development of the 

 stolon, it will be well to describe the appearance of the mature 



