342 ON GENERATION. 



to the effect, as some parts produced by epigenesis are poste- 

 rior in order to other parts, and are different from antecedent 

 parts, as effects differ; so does it seem probable that efficients 

 also vary : from things that produce different operations, dif- 

 ferent motions likewise proceed. Thus physicians in their 

 physiologies assign certain organs as the agents of chylification, 

 others of sanguification, others of generation, &c. ; and anato- 

 mists speak of the ossific, carnific, and neurific faculties, which 

 they conceive produce bones, flesh, and nerves. 



But in the generation of the chick, of several actions differ- 

 ing not a little from one another, it is certain that the efficient 

 causes must also differ ; those that present themselves to us as 

 accidental efficients of generation must nevertheless be neces- 

 sary, seeing, that unless they are associated or intervene, no- 

 thing is effected ; those, to wit, are rightly held " efficients " 

 which, whilst they remove external hinderances, either cherish 

 the conception, or stimulate and turn mere potentiality into 

 positive action. Under this head we should arrange incuba- 

 tion, the proper temperature of the air and the place, the spring 

 season, the approach of the sun in the circle of the zodiac ; in 

 like manner the preparing causes which lead the vitellus to 

 rise, make the macula to dilate, and the fluids in the egg to 

 liquefy, are all properly held " efficients." 



Further, to the number of efficient causes are to be rec- 

 koned the generative and architectonic faculties, styled parts by 

 Fabricius, viz., the immutative, the concoctive, the formative, 

 the augmentative, as also the effective causes of certain acci- 

 dentals, viz., that which constitutes the pullet male or female, 

 like the father or the mother, taking after the form of the first 

 or last male having connection with the mother; that too 

 whence the offspring is an animal ; whether perfect or defective ; 

 robust and healthy, or diseased ; longer or shorter lived ; keep- 

 ing up the characters of the race or degenerating from them ; 

 a monster, an hybrid, &c. 



Lastly, when we were discussing the efficient causes of the 

 foetus, we were not inattentive to its admirable structure, to 

 the functions and uses of all its parts and members ; neither 

 did we overlook the foresight, the art, the intelligence, the 

 divine inspiration with which all things were ordained and 

 skilfully continued for the ends of life. It is not enough that 



