SEASONS AND ORGANS. 187 



the male, although there is no insertion ; and in the roe-fish it would 

 seem to arise from the rubbing their belly against some hard body. 



Mental Influence over the Act of Generation. 



The act of generation arises from two causes of motion : one an 

 internal stimulus in quest of external influence, the other external 

 and mechanical. A strong effect upon the mind by means of nerves is 

 capable of doing it; so that the action of the nerves is similar to 

 external influence. A dream does it more completely, which is a 

 stronger action of the mind than when awake ; for, when awake, the 

 mind is fluctuating between the delusion of idea and the truth, which 

 only produces half the effect ; but in the dream it is all idea, or the 

 mind is allowed to act on the parts with full force ; therefore the nerves 

 do not act of themselves, they only become a stimulus to other parts. 



Relative Pugnacity of the Sexes when in Heat. 



Most males fight for their female when she is in heat ; but I believe 

 no two females in heat fight for the male : — the human perhaps may 

 be considered as an exception to this rule ; but, if it is, it most probably 

 arises from reason joined with the strong principle of desire of being 

 possessed. 



On the Seasons for Breeding. 



Animals which are obliged to have recourse to the fruits of the earth 

 for food for their young, breed early or late according to the season for 

 their respective foods, which ' season ' generally includes warmth ; and 

 animals which have the power of provision within themselves, breed 

 according to the warmth of the season, joined with the modes of pre- 

 serving their own heat, either by the economy of the parent, as [exem- 

 plified in the nests of] mice, rats, &c, or by their own covering, as in 

 the case of lambs, &c. 



Warmth brings forth seeds faster than cold, therefore there is no 

 determined time for their development, but that which relates to heat. 

 Warmth also brings forth insects from the egg sooner than cold, and 

 makes eggs hatch faster. But does a warm climate make a woman go 

 less than nine months ? or a cow, &c, less than the usual time in cold 

 climates ? Precocity in the human species is a consequence of warm 

 climate. 



On the Organs of Generation. 



Relation of Vesiculce Seminales to Size of Testes. — The testes of animals, 

 with or without vesiculee seminales, are pretty much upon a par with 



