TUBULARIA. 23 



ration of that important organ, surely it would be a most interesting 

 question — " Did the heart decay by nature, or was it violently reft from 

 the carcase ?" The hydra of the zoophyte is to its existence as the heart 

 in the quadruped. 



Effect of Wounds and Lacerations. — A blood-red spot generally re- 

 mains below the point of separation in the pith, from whence a head has 

 naturally fallen. But this is not an internal embryo rising to displace the 

 head ; it seems only a residue of that obtuse prolongation of the disc de- 

 scending into the stalk, or of the pith itself which had joined the head. 

 This descending stump, which is inserted for about a line into the stalk, is 

 sometimes withdrawn entire from the tube as a part of the hydra, then 

 quitting that sheath as an independent substance. The pith under its 

 greatest consolidation is very tenacious. A perfect portion extending nine 

 lines, fell out of a section of the stem after it was sundered ; likewise, 

 portions entire may be blown out of short sections by the mouth. The 

 former of vivid red was nearly as solid as flesh ; at least, much more con- 

 sistent and more tenacious then jelly. Part of the pith seems always to 

 separate along with the deciduous head. 



The regeneration of the ovum in the cyst being void of probability, 

 and as the fall of the head in our cabinets, without violence, produces the 

 same nodes or articulations of the stem as are found on specimens with- 

 drawn from the deep, the elements of a new head to replace the old one 

 should be preparing on purpose, that perpetuation of the race shall con- 

 tinue. 



Experiment seems to confirm the fact. In the natural state only a 

 single head can subsist on a stalk. More than one at a time is the result 

 of monstrous conformation ; nor does this appear once among five hundred 

 specimens. Indeed, I have never witnessed it above twice or thrice 

 through a very long series of observations. In the first instance, a much 

 smaller head issued from the side of a stalk than that crowning the sum- 

 mit, and about half an inch lower. Another specimen afforded an example 

 of two stalks, about half an inch long, issuing from a common aperture 

 still lower in the side of the main stem, and diverging as they rose. — 

 PI. IV. fig. 25. A third consisted of a stalk, five or six inches high, forking 



