48 ZOOPHYTES. 



not but excite doubts and difficulties : Nor can we tell what tests are 

 authoritative. Degeneration itself alters the appearance of specimens so 

 much, that it is scarcely possible to class them with the more vigorous of 

 the race. Yet degeneration does not merely result from that exhaustion 

 of the elements of evolution which seems concomitant on successive repro- 

 duction. But, as an unsuitable soil and climate reduce gigantic vegeta- 

 table products to dwarfs, or absolutely preclude their germination, so is 

 the growth of all zoophytes repressed by an unfavourable position. Some 

 of the more prominent features distinguishing certain species may be thus 

 obliterated. Without a profusion of specimens, our doubts cannot be re- 

 solved, and such specimens must be of that description, besides, as to ad- 

 vance from greater imperfection to superior quality. 



A group of about 20 specimens vegetated through some spongy mat- 

 ter wherein the roots were involved. No whirls distinguished any por- 

 tion of the stalk ; but the course of reproduction was infinitely quicker 

 than in the Tuhularia indivisa, and the hydrae had all the characters of 

 the larynx. None of the stalks were connected by bars. Unless for 

 the speedy reproduction, these might have been thought dwarf indivisa. 

 —PL II. fig. 15. 



The Tuhularia larynx is infested by dangerous enemies. During 

 the frequent regenerations of the fine and ample specimen first described, 

 a very numerous colony of a certain kind of Doris, which shall come under 

 cognizance in its proper place, menaced its destruction. These little crea- 

 tures, also consuming the epidermis of the Tuhularia indivisa, now nestled 

 among the most intricate recesses of the mass, whence they could not be 

 otherwise dislodged than by a slight putrescence imparted to the water, 

 compelling them to forsake their haunts below in quest of a purer me- 

 dium. Thus were 68 diminutive parasites captured and removed. Re- 

 peated lotions cleansed and purified the tuft, so that regeneration con- 

 tinued. But the ravages of the Doris had been great, and clusters of its 

 spawn remained inaccessible. 



