APPENDIX. 105 



kinds of Entozoa, many of which are restricted to parti- 

 cular organs of particular species of animals, and are 

 themselves the theatre of existence to other parasitical 

 beings ! 



Here, as Dr. Holland emphatically remarks*, we 

 approach to speculations, which, though founded on the 

 most minute forms of existence, have yet a vastness in 

 their obscurity, and in the results to which their solu- 

 tion would lead. Hence the questions arise, whether 

 animal or vegetable life, (for the inquiry equally regards 

 both), is in any case produced, except from the eggs or 

 germs of prior individuals of the same species ? whether 

 there may not be matter so constituted, as to be capable, 

 from the influence of some unknown law, of assuming 

 an organic character, and giving rise to particular 

 species of living beings, whenever the conditions suit- 

 able to the development and continuance of such organ- 

 isms are present? The theory of the origination of 

 living beings from inorganic elements, or, to use the 

 expression of the author of the " Vestiges," " of organic 

 creation by law? offers a solution to these difficult 

 problems; but no certain evidence has yet been ob- 

 tained to substantiate, or even sanction this hypothesis. 



* Medical Notes and Reflections, p. 579. 



