SERTULARIA. 153 



swelling slightly, which augured similar configuration as the other. — 

 PI. XXIV. figs. 5, 6 ; fig. 7, enlarged. 



The root, also, was losing its density. At first an opaque, flattened 

 spherule, it becomes a thinner spot : ramifications diffuse within its circuit, 

 very conspicuous in early stages, but growing daily fainter and less dis- 

 tinct, until disappearing in attenuation. On May 15, the under surface of 

 the spot had broke into five ramified processes, which I can scarcely com- 

 pare to radicles, some of them apparently preparing subdivisions, all deep 

 yellow, darker towards the centre, and paler towards the extremities, these 

 being still bounded by a circular outline, fig. 8, enlarged. 



The nascent specimen, fig. 7, had acquired a second cell on May 15, 

 a third on the 22d, and soon afterwards a fourth. Many stems had two, 

 and a few had three ; but this specimen vegetated no farther, — Figs. 9, 

 10, 11, 12. Natural size, and enlarged. 



Recurring to the tall glass jar, wherein eighteen planulse were enume- 

 rated upon the bottom, on May 10, all were motionless on the 14th, 

 though next day five or six still showed symptoms of animation. On this 

 day, also, some bright yellow spots, each -wiih a central spine, appeared 

 just about the place the planulae had occupied ; but none could be disco- 

 vered on the side of the vessel. 



Being less versant then, in the history of Zoophytes, from practical 

 observation, the relation between the living planulae, endowed with volun- 

 tary motion, and the stationary spots substituted for them, were to me very 

 perplexing. 



All the spots with a central spinous process were affixed to the bot- 

 tom of the vessel ; but my perplexities were aggravated by next day ob- 

 observing a short spine shooting from the summit of several of the com- 

 pound vesicles on the suspended branches. 



Under the microscope, these spinous processes corresponded with the 

 subjects of previous observation. Nothing farther was seen but the vas- 

 cular pedestal, bearing the spherule, whence the yellow spine issued, 

 which was not evidently connected with either the pedestal or the branch. 

 — PL XXIV. figs. 13, 14 ; spherule, a ; pedestal, b, enlarged. 



Besides these globules, from which a spinous process issued, a stalk 

 VOL. I. u 



