[lloyd] 



ORIGINATION OF ASCIDIA 



75 



Case 10. (figure 11). Incomplete ascidium on both internal lobes; 

 on the left, a fold of the blade athwart the mid-vein, (figure 11a, 

 section through a-b) ; on the right a nearly complete ascidium but 



united with the chief lobe by a bridge of tissue (figure 12c) pertaining 

 to the morphological lower (dorsal) side of the leaf. The auriculate 

 sinus between is therefore closed by a diaphragm. The topographic 

 relations are shown by figures 12 to 12d inclusive; figure 12a, section 

 g-h; 12b, e-f; 12c. c-d; 12d, a-b. 



Case 11. (figure 13). Nearly complete ascidium on chief lobe above: 

 transverse folds and notches; on one side only a cicatrix displaying 

 free margins ("enations") (figure 7) near the base, but closed above, 

 indicates a partially formed second (basal) ascidium. Figure 7a is 

 from a section through a-b. Some histolysis, due to stresses between 

 the concrescent parts, is evident. 



