40 ZOOPHYTES. 



Fig. 20. Hydra in an early stage, developing in a stellate form from its 

 embryo state; enlarged. 



21. Nascent Tubularia, — tentacula still clavate, enlarged. 



22. Nascent Tubularia farther advanced, — oral palpi, a, originating, 



enlarged. 



23. Nascent Tubularia, — the tentacula nearly symmetrical, front, en- 



larged. 



24. Nascent Tubularia, sustained on the tentacula, — oral palpi un- 



folding, enlarged. 



25. Nascent Tubularia, still free, — organs almost symmetrical. 



26. The same enlarged. 



27-34. The figures inclusive represent young Tubularise bred from the 

 cyst, in January 1841, in various positions, all rooted. 



35. Young Tubularia (fig. 28 enlarged), with irregularities near the 



root. 



36. Young Tubularia bred from the cyst. 



37. Another. 



38. Young Tubularia bred from a cyst of fig. 18. 



89. Young Tubularia bred with 15 tentacula from the cyst. The ten- 

 tacula of the regenerated hydra succeeding it were only 7. 



40. Young Tubularia bred from the cyst in 1832. The hydra sub- 



sisted 21 days. 



41. Upper portion of a young Tubularia, with a renovated hydra, 



which is rising from the stem. 



42. Young Tubularia bred from the cyst, enlarged. 



43. Prolific Tubularia — natural eize. 



Plate IV. — Redintegrations of the Tubularia Indivisa. 



Fig. 1. A hydra or head generated from an artificial cleft. 



2. The original stalk of fig. 1, having been previously cut asunder, 



the hydra of this fig. 2, was generated from the summit of the 

 lower half. 



3. Head generated from the same lower half, after fig. 2 fell. 



4. Summit of the regenerated neck in decay. 



5. The lower half of fig. 2 having been sundered, a hydra was gene- 



rated from the summit of this section. 



6. Another hydra, generated from the same summit of fig. 5, in suc- 



cession to the former, the shoot having prolonged. 



