C. M. CHILD. 



than in those which have none, but my data indicate that trans- 

 formation will occur to some extent in any stock with sufficiently 

 high concentrations of the agent used and sufficient time. Lack 

 of material limited experiment with this species. A few examples 

 are given. 



Pieces in HC1 772/2500 (pH 7.3) still possess some hydranths 

 after four days. A few short outgrowths, apparently intermediate 

 between stems and stolons have developed but no typical stolons. 

 These pieces were then changed to HC1 777/1500 pH 6.8 and 

 after two days more showed numerous stolons in the more basal 

 regions and outgrowths apparently intermediate between stolons 

 and stems in the apical regions. These intermediate outgrowths 

 are straight, support themselves free in the water and do not 

 adhere to surfaces as do the stolons, but they show no annulation 

 and they develop quite independently of hydranth buds (Fig. 12). 



Fig. 13 shows the development of stolons in the basal region 

 of a stock after a week in ethyl urethane m/2OO. In ethyl urethane 

 772/500 transformation did not occur within a week. Figure 14 

 shows stolon development in the apical region of a stock after 

 ten days in standing water. This stock bore numerous gonozo- 

 oids in the basal regions. 



TRANSFORMATION IN Obelia. 



In Obelia borealis transformation was observed in HC1 772/1500, 

 LiCl 772/50, chloretone 772/2000, neutral red and also in standing 

 water, but in water the stolons are less numerous than in the 

 various solutions and after a few days new hydranths develop. 

 In neutral red all parts stain opaque black, the hydranths disin- 

 tegrate or are resorbed and stolons which are opaque black like 

 other parts develop in large numbers. In this species stolons 

 may be either terminal (Figs. 15, 16) or in the axils of branches 

 (Fig. 17). Usually when they attain a certain length they sepa- 

 rate from the parent stock, fall to the bottom and the tip con- 

 tinues to grow at the expense of lower levels until reduction to 

 minute size and exhaustion occurs, or, if inhibiting conditions are 

 removed, they may give rise to hydranth and stem. 



Obelia geniculata behaves essentially like 0. borealis as regards 

 transformation and the stolons are of the same type in the two 

 species. Another unidentified campanularian showed extensive 



