the effect of its expansion, by which the membrane which confines 

 it is ruptured. An expansion, sub coitu, may happen, from the 

 general determination to the uterine system at this time, and a 

 more particular determination to the ovum itself may be supposed, 

 in agreement with the theory before suggested, viz. that, sub coitu, 

 the semen of the male and the maternal ovum acquire, as points of 

 confluence, properties from every seat in the structure of the 

 parents. It is not supposed that these resembling or radical pro- 

 perties have a material bulk, by the addition of which to the ovum 

 it might be expanded ; it is, in agreement with this theory, con- 

 jectured only, that, as in other instances of spiritual determination, 

 as in cases of sympathetic irritation, &c. an increased determination 

 of fluids succeeds to that of the spiritual properties. But whether 

 the ovum escapes by an expansion which ruptures its capsule, or in 

 any other way, is for the present purpose of very little consequence. 

 Its escape is accomplished by an act, or change, of vital properties, 

 on the part either of the maternal contiguous structure or of the 

 ovum itself; since the same cause, viz. that of fecundation, would, 

 produce no escape of an ovum in the dead subject. 



26. The ovum next passes into the uterus: which we may 

 imagine to result from the exercise of a faculty of contraction 

 possessed by the Fallopian tubes, propelling it to its destination. 

 We have no reason to think that this journey is one which the 

 ovum itself has wit enough to perform, seeing that it was never in- 

 structed of the road, and has not yet acquired its travelling members, 

 whether by wings, legs, fins, on horseback, or in a mail-coach. So 

 much for these matters: it is enough that this act too is one of 

 vitality. It is a function of the uterus to prepare a membrane for 

 the reception of the ovum, which is very civil on the part of the 

 uterus, but is nothing to us at present. It may however be re- 

 marked, that this formation of a membrane is another result of the 

 determination just spoken of, and exemplifies a common ending of 

 determination, in secretion. Our present business is with the growth 

 of the ovum. 



27. The ovum, while it is yet an homogeneous aggregation of 

 animal substance, destitute of any intelligible arrangement, attaches 

 itself to the uterus in such a manner as to obtain blood or some 

 other fluid : and this forms another epoch in the causation which ter- 

 minates in foetal life. 



28. Blood supplied to a dead ovum will not lead to the for- 

 mation of the textures, nor produce any change in it except that 

 perhaps of making it contain a little blood: and yet the organiza- 

 tion of the ovum might be preserved, so far as it is visible (the best 

 analogous example will be found in the crustaceous ova, &c.) It is 

 then, as demonstrated before in another way, the principle of life, or 

 the organic spirit, which leads to those changes, by which the tex- 

 tures, &c. are formed. 



29. Nor are the properties of the spirit gradually conferred 

 upon the ovum by an intercourse of circulation, &c. which obtains 



