420 HISTORY OF ZOOPHYTOLOGY. 



in this department of natural history. In several essays pre- 

 sented subsequently to the Royal Society, and published in 

 their Transactions, he continued to illustrate and extend his 

 opinions, and defended them so successfully against his oppo- 

 nents, that they soon came to be very generally adopted. 



There was nothing unformed nor mystical in ElhYs opinion. 

 Certain marine productions, which, under the names of Litho- 

 phyta and Keratophyta, had been arranged among vegetables, 

 and were still very generally believed to be so, he maintained 

 and proved, with a most satisfactory fulness of evidence, to be 

 entirely of an animal nature the tenements and products of 

 animals similar in many respects to the naked fresh-water 

 polype. By examining them, in a living state, through an 

 ordinary microscope, he saw these polypes in the denticles or 

 cells of the zoophyte ; he witnessed the display of their tenta- 

 cula for the capture of their prey, their varied actions and 

 sensibility to external impressions, and their mode of propaga- 

 tion ; he saw further that the little creatures were organically 

 connected with the cells and could not remove from them, and 

 that although each cell was appropriated to a single indivi- 

 dual, yet was this united " by a tender thready line to the 

 fleshy part that occupies the middle of the whole coralline, 1 ' 1 

 and in this manner connected with all the individuals of that 

 coralline. The conclusion was irresistible the presumed 

 plant was the skin or covering of a sort of miniature hydra ; 

 a conclusion which Ellis strengthened by an examination of 

 the covering separately, which, he said, was as much an ani- 

 mal structure as the nails or horns of beasts, or the shell of 

 the tortoise, for it differs from " sea-plants in texture, as well 

 as hardness, and likewise in their chemical productions. For 

 sea-plants, properly so called, such as the Algse, Fuci, Sic., 

 afford in distillation little or no traces of a volatile salt ; 

 whereas all the corallines afford a considerable quantity, and 

 in burning yield a smell somewhat resembling that of burnt 

 horn and other animal substances, which of itself is a proof 

 that this class of bodies, though it has the vegetable form, yet 

 is not entirely of a vegetable nature.'"* 



* Dr. Good is in error when he states that the ammoniacal smell from burnt zoo- 

 phytes was the principal fact for placing them in the animal kingdom. Book of Na- 

 ture, i. 175 and 210. 



