VoL. 2] Torrey—The Behavior of Corymorpha. 337 
on one side, or alternately on both sides. The stem was then 
laid on the floor of the aquarium, a cut side uppermost. In one 
to two hours, the stem had assumed an erect position. The cuts 
were intended to destroy the effectiveness of the muscles of the 
stem, leaving the column of axial endoderm cells intact. The 
muscles as a whole were weakened by the cuts. And the slowness 
of the reaction, coupled with the fact that the orientation was 
accomplished before the wounds closed, strengthened the view 
that muscles were not concerned in the reaction. 
Other facts supporting the same conclusion have since been 
obtained. A piece was removed from a stem by two cuts which 
1 2 3 
formed with each other an obtuse angle (fig. 1). On the cut 
faces, the axial endoderm was exposed. The rounded surface 
representing the original stem wall was still covered with ecto- 
derm, provided with longitudinal muscles. Figs. 2 and 3 were 
drawn from this piece when it was in contraction and expansion 
respectively. It will be noticed that in the contracted condition 
(fig. 2), the course of the longitudinal muscle fibers is no longer 
