TUBULARIA. 31 



nerally find it difficult to understand the cause of supernatural enlarge- 

 ment, diminution, multiplication, and distortion. Symmetry itself seems to 

 result from an original harmonious arrangement of the constituent parts 

 of the elementary organs, and their regular developement following the 

 institution of life : — deformity from some disturbance received during 

 the progress of their evolution. But if symmetry be not altogether an 

 artificial character, expressed by an arbitary term, there is, in truth, for the 

 most part, throughout the universe, only an approximation towards it. 

 Regardless of minutiae, when these approximations are close, we hastily pro- 

 nounce on identity. Still, how seldom is any pair of human organs or 

 any subordinates of these organs alike ? Amidst a thousand leaves or 

 flowers we cannot mistake one of any two for the other, on the due exer- 

 cise of our perceptive faculties. Therefore it would be remarkable, after 

 the violent divulsion of organic structures, to find its effects totally oblite- 

 rated by reunion of the parts. Wounds may be inflicted which cannot 

 heal, spite of the wonderful energies of living matter. 



The stalk of a specimen having been cleft down from the summit, no- 

 thing followed. Afterwards it broke over, but without separating at the 

 point of fracture, and the cloven summit hung lowest by the side of the 

 upright stem. There were now two summits, one originally the under 

 part of the cloven portion, which portion was there inverted, the other the 

 upper part of the fractured stalk. A hydra issued from each. The sum- 

 mits were unconnected, but the two hydrae were conjoined by the union of 

 the oral palpi of the one to the pouch of the other. — PI. II. fig. 14. As 

 both parts of the ruptured stem were previously upright, the hydra now 

 issuing from the point opposite to the cleft was opposite to what would 

 have been its direction by regular and undisturbed reproduction. The 

 larger and more perfect hydra developed from the main stem in its natu- 

 ral direction ; the other was inverted. On the 1st of January the rudi- 

 ments of reproduction were visible from the cleft of a specimen which had 

 been made a month previously ; and a head veith 14 tentacula, but without 

 oral palpi, burst on the 7th. The latter developed, however, and the head 

 become symmetrical, decayed on the 15th. A second head regenerated 

 from a, the same half of the cleft, on May 3, which fell on the 6th. — PI. IV. 



