Manchester Memoirs, Vol. xli. (1896), No. 1. 11 



which have arisen by unequal division, it is clear at a 

 glance that the two strands of xylem are very different 

 from one another. The normal stele needs no description. 

 The other presents a xylem, semi-lunar in form, with 

 small elements on the flattened side, and much larger 

 ones on the convex side. The number of preparations 

 of this type of stele is not large, and their phloem is 

 not clear enough to justify a definite statement ; but two 

 or three of them have raised the suspicion that the phloem 

 is mainly, if not entirely, restricted to the convex side 

 of the xylem. It is somewhat tantalising that the 

 preparations should fail at this important point, because, 

 as will be seen below, the nature of the member to which 

 this stele belongs depends, at least in part, upon the 

 symmetry of the stele. It is important, therefore, to 

 decide whether the latter is radially or bilaterally sym- 

 metrical. 



Lastly, in No. 115, we have two distinct and complete 

 structures, lying near to one another, whose steles corre- 

 spond respectively to those found in the same axis in 

 No. 101. 



In No. 105 (Fig. 2), in addition to the two steles 

 already described, a third structure is found in the 

 cortex, which is obviously some organ which, originating 

 at or near the bifurcation, is on its way from the central 

 cylinder to the surface. Coming off obliquely, its section 

 is an oblique one, but in it we can easily distinguish 

 both a central cylinder and a cortex. The cortical cells 

 seem to have had thin walls and copious cytoplasmic 

 contents, as if full development had not yet been attained. 

 The central cylinder is not at all well defined, but I 

 suspect it carried a diarch xylem strand. The real nature 

 of this organ is not quite certain, but its endogenous 

 origin leads me to think it is a root. Moreover, in several 

 preparations, Nos. 102 and 103, for example, sections of 



