Davknport. — Cristatella. 



PLATE II. 



Ail figures are magnified 390 diameters, and are from sagittal sections. 



Fig. 8. Stage II. in the same series as Fig. 2. The funiculus, fun., has moved 

 farther from the mother polypide. Margin to left. 



" 9. Stage IV. The inner layer, i., of the bud is definitely formed, and the 

 external layer is greatly thickened. Margin to left of figure. 



" 10. Stage V. The cells, i., have arranged themselves in a layer, and begin 

 to form an invagination. Margin to right. 



" 11. Stage VIII. The first indications of the alimentary tract appear as a 

 depression in the inner layer, rt. The funiculus, cl.fun., has begun 

 to form, as is indicated by a disturbance of the coelomic epithelium. 

 Daughter bud forms Stage VI. in a series beginning with I., Fig. 3. 

 Margin to left. 



" 12, 13. Successive stages in the formation of the alimentary tract. 



" 14. Stage VI. The two cell-layers are now definitely formed, and a lumen 

 has begun to appear in the inner. Margin to right. 



" 15. Stage III. in the stoloniferous type of budding. Stolon has elongated 

 greatly, and active cell division is taking place at its distal (i. e. mar- 

 ginal) end. 





