66 THOMAS HICK, B.A., B.SC, A.L.S. 



EXPLANATION OF FIGURES ON PLATE IV. 



Fig. 1, Transverse section of Rachiopteris, showing undivided stele. This 

 photograph is taken from slide No. 104 of the Cash Collection in 

 the Manchester Museum. 



Fig. 2. Transverse section, showing division of stele into two equal parts 

 (Cash Coll., No. 105). 



Fig. 3. Transverse section, showing unequal division of stele (Cash Coll., 

 No. 103). 



Fig. 4. Transverse section taken a little higher up than section 3, showing 

 beginning of separation of the two unequal steles (Cash Coll., No. 

 102). 



Fig. 5. Transverse section, showing completion of division of the stele (Cash 

 Coll., No. 101). 



Fig. 6. Photograph of a larger portion of slide No. 102, than in Fig. 4 show- 

 ing two stems, A and B, with their offshoots ; a and r are probably 

 lateral roots ; and s is a lateral structure of unknown nature. 



