Manchester Memoirs, Vol. lix. (191 5), No. 3. 15 



series of a large plant in this plane are represented in out- 

 line in Fig. 3 A — D. In A, which is the median section, 

 the position of the depressed apex and the relation to this 

 of the developing leaves and the functional leaves is seen 

 above, while the position of the groove and the plane 

 of the progressive splitting is recognisable below. The 

 vascular axis is clearly distinguishable into the region 

 belonging to the stem and the lower rhizophoric region. 

 The junction of the two regions has been broadened by a 

 process of stretching involving rupture of the tissues. A 

 well marked zone of secondary prismatic tissue has been 

 developed around the older portions of both the stem 

 stele and the rhizophoric stele. The plane of this section 

 did not follow any of the orthostichies of root-traces and 

 only indications of older leaf-traces were seen in this 

 section. In the section represented in Fig. 3 B> however, 

 the position of the developing roots and the course of the 

 root-traces are shown. It is noteworthy with regard to 

 these that the roots are developed a short distance below 

 the lower end of the vascular axis, close to the lower 

 meristem. The root-tips at first point towards the plane 

 of the future split and, on this taking place, stand at right 

 angles to the exposed surface. The course of the root- 

 traces in the cortex corresponds to this, being curved until 

 the root-tips are exposed on the surface and then nearly 

 straight. The roots stand in acropetal order in relation 

 to the downwardly growing rhizophore. The arrangement 

 of the young roots and the root-traces thus exhibits a 

 striking correspondence with the relations of the young 

 leaves and their leaf-traces to the depressed growing point 

 of the shoot. These points are further illustrated in Fig. 5 

 which represents a median longitudinal section in the 

 plane of the lobes through a smaller but complete plant. 

 The other two sections in Fig. 3 are sufficiently far 



