TUBULARIA. 21 



new shoot had elongated nine lines, and the wound had been inflicted six 

 lines below the disc. Now a slight enlargement became sensible below 

 the site of the wound. In twenty days a new head, still invested by its 

 spath or involucrum, though three lines high, was unexpectedly issuing 

 from the stalk, and burst next day with twenty-two tentacula, its pre- 

 cursor had only twenty, and it proved a fine specimen. 



This regeneration had suffered nothing from the previous wounding of 

 the stem, either because the minuteness of the germ had eluded the edge 

 of the instrument, or, which was more probable, because the early bud had 

 not rose high enough to be injured. 



Root. — Little is to be explained regarding the root of the Tubularia. 

 Its origin seems subordinate to that of the head : it advances downwards, 

 and extends superficially. But the vegetative principle here, so conspicu- 

 ous and so vigorous in plants, is apparently much more feeble in this ani- 

 mal product. Zoophytes, it must be remembered, have no proper pene- 

 trating or spreading root, comparable to that which is reinforced by acces- 

 sories in the other kingdom. The root of the Tubularia indivisa runs in a 

 kind of irregular cylindrical form, somewhat distorted, insomuch, that Ellis 

 describes the subject as arising " from small worm-like figures, many of 

 which interwoven together, look like the guts of small animals." He 

 alludes hereby to the congeries descending from a group, for the root of an 

 individual specimen is single, appearing simply an opaque yellowish, more 

 solid and compact prolongation of the stem. Such prolongation is seldom 

 seen in an artificial state, nor, when it does ensue, is the adhesion alike 

 firm as in the natural state, where it is very strong. Extension of the 

 stalk above depends exclusively on the evolution, together with the dura- 

 tion of the head, for the increment of the one is regulated by the subsis- 

 tence of the others. But, as far as can be ascertained, its prolongation 

 downwards is independent of either ; nor is it ever so rapid and evident. 

 Both the extension and the diameter of the root augment with age as de- 

 monstrated in older specimens : its course is always superficial, sometimes 

 descending over the edge of what may sustain it, but scarcely sinking the 

 least into the surface of shells of softer substance. There is no diffusion 

 of parts here as with the root of some nascent Sertularice. 



