question, in the hope, of reflecting upon it some additional light. 

 The temperature of an egg may be raised in a few minutes to the 

 same degree as that which it attains during any period of incubation ; 

 and yet none of those formations, as bone, muscle, membrane, &c. 

 will take place, which happen eventually. If the properties of the ovum 

 were predisponent, waiting each for a cause which would perfect their 

 identities, it would appear that each being supplied with this cause, 

 should then be in a condition for commencing the operations which 

 terminate in foetal existence; it appears that this should be the case, 

 if the properties did not act because they were deficient identities, 

 that is, deficient in regard to the purpose which they ultimately 

 accomplish; and if heat, which, so far as we know, has no other 

 varieties but those of degree, perfected these identities, then the 

 temperature of incubation once attained, the properties should re- 

 quire nothing further in order to exert themselves to the end of 

 foetal existence. 



20. But this is not the fact, for a continuation of heat is 

 necessary to the end of foetal existence ; from which it appears war- 

 rantable to infer, that heat does not operate on individual properties 

 by supplying a cause, in which they were deficient, in the way of 

 true or individual causation, but by continuing an influence which 

 maintains the series of processes which take place between the 

 .properties which are inherent in the ovum. 



21. Thus then, in consideration of these preceding proofs, it 

 may be presumed as probable that all the properties of the future 

 .animal acg possessed by the ovum; that its changes are those of 

 combinations, among these properties, inherent processes of causa- 

 tion, which we are further to consider. 



22. The maternal ovum by fecundation is advanced into the 

 second stage of pre-disposition* towards foetal life. Its latent pro- 

 perties are increased by the acquisition of the differentials spoken of 

 (at 11, 12, 13, &c.), and its acting properties are also increased by 

 the change of combination which the properties of its organic spirit 

 undergo. 



23. The cause of fecundation makes the latent properties of 

 of the maternal ovum active; it unites its own properties with 

 them, and they proceed in a series of changes according to their 

 spiritual relations. 



24. We can remark nothing further of these spiritual relations 

 than has been already remarked at 15, where they are reduced to 

 common principles of causation, on the truth of which they are 

 rested. But although we do not know all the agencies which are 

 involved in a single spiritual process, yet we are able to infer some 

 changes which display themselves in the visible alliances ; our busi- 

 ness will be to trace these changes, making such inferences. 



$ 25. The escape of the ovum from the ovarium is probably 



This pre-diiposition refers principally to future internal changes by 

 properties possessed. 



