THE INFLUENCE OF GRAFTING ON THE POLARITY 



OF TUBULARIA 



FLORENCE PEEBLES 



With Twenty-Six Figures 



The experiments made by Loeb, Driesch, Morgan, and others, 

 have demonstrated that by closing the oral end of a piece of the 

 stem of Tubularia the development of the aboral hydranth is 

 hastened. The same result was obtained by Morgan ('03) when 

 he bent long pieces in the middle, or ligatured them so that the 

 coenosarc of the two ends was completely separated. Morgan 

 and Stevens ('04) have shown further, that the formation of a 

 hydranth at the aboral end of a piece produces a change in that 

 region, so that when this hydranth is removed, the piece is more 

 likely than before to develop another aboral hydranth. 



The object of the experiments described in this paper was 

 primarily to determine what influence grafting exerts upon the 

 polarity of Tubularia mesembryanthemum, but one experiment 

 led to another until the investigations extended to a study of some 

 of the factors of regulation. 



Last spring it was my privilege, through the generosity of the 

 "Association for Maintaining the American Woman's Table at 

 Naples," to spend two months at the Zoological Station, during 

 which time I carried on the experiments described in the following 

 pages. It gives me great pleasure to express here my gratitude 

 to the Association, and also to Prof. Anton Dohrn, and the other 

 members of the staff at Naples, for the courtesies extended to me 

 during my stay. 



In eadier experiments in grafting ('00 and '02) two compo- 

 nents having the same diameter were selected, the two cut sur- 

 faces were applied, and held together until the ccenosarc united. 

 This method proved so tedious that a new one was adopted. In 



The Journal of Experimental Zoology, vol. v, no. 3 



