128 ZOOPHYTES. 



Thus, more than two in adhesion, Plate XVIII. figs. 16, 17, fell 

 from fig. 12. On another occasion two united, showing no disparity in 

 the number of arms separated from a different roll. 



A monstrous Medusa consisted of two bodies united by a fleshy neck, 

 the one body with four, the other with ten arms. — Plate XX, fig. 24. 



Are the four sets of flexible organs on the under surface rudimentary 

 appendages ? — PI. XVIII. figs. 4, 5. 



Although by repeated, long, and painful observation, I have endea- 

 voured to learn the history of the Hydra tuba, and the McdmcB originating 

 from it, my purpose has been but partially attained. I have selected many 

 individuals, and I have chosen colonies of both to discover whatever changes 

 they should undergo. The hydra grew, it fed, it bred, its existence was 

 long. The Medusa lived, it neither fed nor bred, its existence was infi- 

 nitely shorter ; nor did it undergo the smallest change from the first mo- 

 ment of liberation for 55 days. Its life could not be protracted, on any 

 occasion, beyond 60 days. 



Between the form and habits of these two animals there is not the 

 smallest correspondence. 



At the commencement of my observations many years ago, I was not 

 aware, as already said, of the Medusa having been seen by Bastcr, previous 

 to the year 1765, and distinguished by him as Medusa minutissima . 

 Therefore I named it Medusa bifida provisionally, from the cloven lobe. 



Names already given, if significant, should not be capriciously 

 changed ; and as nothing but the pursuit of tmth ought to be the object 

 of literature, so should naturalists always contemplate that laudable end, 

 by endeavouring to penetrate the works of the great Creator, instead of 

 engaging in controversies — an idle occupation at best. 



My special purpose is now to explain the mode whereby hydraoidal 

 zoophytes multiply their ofiBpring, or enlarge their dimensions, as deduced 

 from examples of the Hydra tuba ; and if the student follows its progress, 

 he will find the subject more easily understood. 



The following conclusions, among others, may be deduced on the na- 

 ture and the relations of the Hydra tuba and the Medusa bifida : — 



