[lloyd] 



ORIGINATION OF ASCIDIA 



73 



displacement in the directions indicated by arrow-points, so that the 

 median vein of the left internal lobe ends at a, and on the right at b. 



Case 2a. (figure 2a). External lobes undifferentiated. A case 

 very similar to case 2 but with suppression of the development of the 

 sectorial areas between the internal and chief lobes, rather than the 

 lobes themselves, that on the right having produced a perfect ascidium 

 distinct from the blade and raised on a cylindrical petioloid stalk. 



Case 3. (figure 3). Constriction of the entire leaf, especially 

 across the region of the external lobes; deep separation between 

 right external lobe and blade, the sinus extending downwards into a 

 ridge along the vein ; the same condition on the left, but less pronounced. 



Had the sinuses and folds met at the base of the leaf an ascidium 

 involving all the leaf excluding only the external lobes would have 

 resulted. Constriction of median and both internal lobes, with notch- 

 ings and foldings. 



Case 4. (figure 4). Internal lobe (of the right side) semiascidiate, 

 resulting from deep constriction and folding. Figure 4a, section 

 through a-b. 



Case 5. (figure 5). Chief lobe semiascidiate. Cicatrix on one 

 side and a long sinus continued into a cicatricial fold on the other. 

 Structure of cicatrix through a-b as in figure 7. 



Case 6. (figure 6). Chief lobe completely ascidiate, the ascidium 

 distant from the bkide. Deep notches on both sides, both continued 

 as cicatrices. Section a-b as in figure 7a reversed. A longitudinal 

 section through the base of the ascidium is shown in figure 6a, in which 

 hypertrophy of the palissade may be noted. 



Case 7. (figure 8). A narrow double-crested ridge, (indicated 

 by a broken line in figure 8; r, figure 8a and b) extending from a sinus 



