TUBULARIA. 35 



This reproduction, c, subsisted until February 25. Another head, with 20 

 tentacula, replaced it on March 5. and decayed in three days. A third, also 

 with 20 tentacula, was reproduced on March 20. and decayed within the 

 same period ; and a fourth, lasting as long, burst with 19 tentacula on the 

 12th of May. The shoot now extended an inch and three quarters, its 

 ruddy tinge gradually faded, when its regeneration ceased. — PI. IV. fig. 13. 



Relative to the latter experiment, it is worthy of observation, that 

 sundering C from B had generated two heads at what was the point of in- 

 tersection of fig. 11, which figure represents B C entire, as composed of 

 figs. 12, 14 ; for, one head vegetated naturally from the higher extremity of 

 C, fig. 14, while another vegetated unnaturally, fig. 12 c, from the point b, 

 whence it had been sundered. These two heads vegetating by ascent and 

 descent, from what had been the same point, flourished at the same time, 

 February 16. and fell at the same time, on the 25th. Both had attained 

 sufficient dimensions ; the rudiments of an ovarium became perceptible in 

 one, which was, besides, very tenacious of life, as it survived its fall eleven 

 days. But that from ascent having 19, and that from descent 18 tenta- 

 cula, it may be conjectured, that although so very remote from the natural 

 site of evolution, the summit of both had originally constituted a single 

 embryo, which, by partition, developed into two, becoming progressively 

 symmetrical in maturity. 



Thus, while A had naturally afforded seven perfect hydrse, besides an 

 embryo, B had generated seven by ascent, and four by descent, and from C, 

 three together with an embryo had ascended. 



Therefore, in the course of 550 days, the single specimen rendered in 

 this manner the subject of experiment, had borne 22 heads, including that 

 subsisting when it was withdrawn from the sea. 



By cleaving a fine stalk D, on November 25, some farther illustra- 

 tions were obtained of the preceding facts. From this, the head, with an 

 ovarium, had already fallen. The wound healed, and in 56 days, a head 

 for some time standing awry, but afterwards gaining symmetry, burst with 

 25 tentacula. — PL IV. fig. 1. It fell in eight days. Another flourished 

 and decayed. Then a third with 21 tentacula, not inferior to the first. It 

 now rose vertically. 



