146 OF THE STRUCTURAL ELEMENTS OF THE HUMAN BODY. 



restoration to their original condition, the chief dynamical agency, which, act- 

 ing through the previously-formed organic structure, enables it to appropriate 

 the former, and thus to supply the conditions needed for the production of nervo- 

 muscular power, the development of which may be considered as the great end 

 and aim of Animal existence. And it is a very interesting exemplification of 

 the correctness of these views, that the rate of recurrence of those "periodical 

 phenomena" of various kinds, which mark the progress of vital activity, should 

 be almost entirely dependent among cold-blooded animals upon external influ- 

 ences, so that they may be artificially accelerated by warmth and retarded by cold ; 

 whereas, in warm-blooded animals, their recurrence is far more regular, the rate 

 of their vital activity being kept at a much more uniform standard, in virtue of 

 their fixed temperature. 1 



[It is questionable whether the views, so ingeniously conceived, and which 

 here and elsewhere 9 are so ably expounded, advance our knowledge of the agency 

 concerned in the production of vital manifestation ; whether, after all, we are not 

 constrained to look beyond a " material substratum/' and the " Physical forces 

 pervading the universe/' for that unknown force which, out of formless material, 

 is capable of evolving forms. Is it possible to regard the organic forms of living 

 beings, bearing the impress of ideas that could originate only in the profoundest 

 wisdom, as proceeding from a force identical with chemical or physical forces, or 

 any mere material force or a necessary result of any material condition ? 



Prof. Jackson dissents, in a published lecture, from the views of the author, 

 and contends for the existence of a peculiar " organic or vital force exclusively 

 manifested in organic or living beings, the dominant principle of organic or 

 vital actions, and the generator of typical organic forms." The essential cha- 

 racteristic of an organic force is, that it must be present in every organized 

 being, and that it shall participate in every organic or life-action. Growth 

 or nutrition, and the production of typical forms are the only phenomena 

 that satisfy these indispensable conditions. Nervous force confined to animals, 

 and restricted in them to nervous organs and apparatus, fails in the attributes 

 of an organic, or life-force. Every organic form is a life instrument, or 

 mechanism; and the combined operations of those which exist in a living 

 organism constitute the phenomena of its life. The forms after which the 

 tissues and organs of organized beings are constructed, are typical, and they are 

 the essential organic phenomena depending on Organic or Vital force, to which 

 nutrition, or the formation of special organizable materials, depending on chemi- 

 cal forces, is subservient. 



The complete separation of typical organic form, and simple nutrition or 

 growth, is shown in polypous or fungoid growths, in cancer growths, and in some 

 cases of monstrosities. In these instances there is rapid production of organ- 

 izable material, and of growth or nutrition, but the cause or force developing 

 a typical form is either quiescent or perverted. There is no organization ; there 

 is structure, but an entire absence of normal tissue and of an organic type. 



The special character of Organic, or radical force of Life is modality, or the 

 power of creating organic forms, the instruments and mechanisms of life. It 

 possesses none of the attributes of the Physical Forces in its action and influ- 

 ences. It has no identity with them : yet there is undoubted correlation. But 

 correlation and intimate dependency do not constitute identity of nature. A 

 clear distinction is apparent between the force that prepares by a chemical action 



1 See, on the subject of the preceding Section, the Author's Memoir "On the Mutual 

 Relations of the Vital and Physical Forces," in the "Philosophical Transactions" for 1850; 

 Mr. Newport's paper "On the Reciprocal Relations of the Vital and Physical Forces," in 

 the "Annals of Natural History," Nov. 1850; and Dr. J. R. Mayer's Treatise "Die organ- 

 ische Bewegung in ihrem Zusemmenhange met dem stoflfwechsel," Heilbronn, 1835. 



2 Princ. of Gen. and Comp. Phys., g 52, Am. Ed. 



