Notes, ii. i6. 183 



nostrils in one respect, viz. as regards the refrigerating process, and therefore probably 

 corresponded to them in others. 



That insects perceive odours is unquestionable. But it is still uncertain where their 

 olfactory organs are situated. It is supposed by some writers at any rate that the 

 stigmata which admit air, and which are mostly "below \hQ- hypozoma" are also the 

 parts which admit olfactory stimulants, " the ultimate ramifications of the tracheae forming 

 one extensive nose." This view (erroneous as I believe) coincides very fairly with that 

 of Aristotle. 



II. A. often speaks of the innate spirit [ijxipvTov irvevna), and distinguishes it from the 

 spirit or breath that is introduced from without (irveC/ua Heiaaicrov). It is however far 

 from clear what his conception of this innate spirit really was. 



There is indeed a special treatise De Spiritu, but this is .most undoubtedly spurious. 

 One sufficient proof of this is that whereas A. in his genuine works gives the same name 

 (<f Ae'jSej) to both arteries and veins, and states positively that they both in life contain 

 blood, the author of this treatise has already learnt to apply the term "arteries" to the 

 former, reserving the term <p\(0es for the latter ; and moreover asserts that the arteries 

 contain air, not blood. The term apr-tjpia in Aristotle always means trachea, or its 

 larger divisions the right and left bronchus, and is never used for any blood-vessel. So 

 again while A. expressly states, in the passage to which this is a note, that the innate 

 spirit is not introduced from without, the author of the De Spiritu says that it varies in 

 amount at different times, and discusses the question whether the increased amount is 

 derived from the food or from the inspired air. Neglecting then this spurious treatise, 

 and putting together the genuine 'passages in which A. speaks, or seems to speak, of the 

 innate spirit, the following seems to me to be his view. 



The " vital heat" which is the immediate agent of the soul in its operations (Z?. G. ii. 

 4, 43) is not common heat, but something with much greater efficacy. The heat of fire 

 cannot effect digestion, cannot convert blood into fat or the like (ii. 6, Note 7), nor cause 

 the development of the embryo (Z>. G. ii. 3, 13). It is only the vital heat, or the celestial 

 heat of the sun, that can do this. Of this heat, derived from the heavenly bodies, there 

 is a store in the air or spirit which is contained in every fluid ; and as everything 

 contains water, "everything is in a sense full of soul " or life (Z>. G. iii. ii, i6). 

 This air or spirit with its stored-up celestial heat is imparted to the embryo in the 

 sperm, of which it forms the active principle; so that "man is produced by man 

 and by the sun" {Pkys. ii. 2, 11), or, in animals generated spontaneously, is imparted 

 in the fluid from which they originate. Thus in all animals it is innate ; and it is 

 on the proportion of this vitalized air or innate spirit that enters into their composition 

 that the greater or less nobility of all animals depends {D. G. ii. 3, 1 1 ). This innate 

 spirit with its vitalizing heat is comparable to, if not identical with, the heavenly aether 

 of which celestial bodies are made (Z>. G. ii. 3, 12), and becomes the agent of the 

 soul in its operations. Its central seat is the heart, and because it is there, this organ 

 becomes the centre of sensation, motion, and vitality generally. 



In short, the innate spirit is the material in which the soul is incorporate, a material 

 akin to, or identical with, the celestial sether. 



A.'s views as to the innate spirit, or innate heat, prevailed for many centuries, and 

 are discussed in Harvey's work on Generation [Exei'cit. Ixxi). 



As regards the mode in which the innate spirit ministers to the soul, the following 

 seems to have been A.'s view. The innate spirit is a suitable agent of the nutritive soul 

 in virtue of its special heat, the use of heat in concoction, growth, development, 

 being evident. It is also a suitable substance to act as the agent of the soul in sensation, 



