284 MONTHLY ABSTRACT OF THE PROCEEDINGS 
what sensation exist, without a heart, arteries and veins ? On 
the one hand, digestion would go on in vain ; on the other, 
absorption would be useless. For were there no arteries to carry 
the newly-formed blood to every part of the body, digestion 
could not support life; so, if veins did not exist to receive 
the refuse matter from the absorbents, nutrition could not be 
perfected.” 
Speaking of the growth of parts, he remarked, “how beau- 
tifully is every particle in the frame deposited, when and where 
required ! Where bone is necessary, osseous matter is laid ; 
fleshy fibre, where muscle is called for ; and cartilage, where 
neither bone nor muscle could be substituted.” Likewise “ the 
simple mechanism of the circulation presents a most beautiful 
display of Nature’s skill; a mechanism w’hereby tissues the 
most different are constructed out of the same fluid; in which 
vessels externally alike elaborate secretions having scarcely one 
character in common. Who has discovered any difference in 
the blood going to the stomach and the kidneys? Yet the 
fluids secreted by those organs are very dissimilar. Again, the 
vessels supplying the brain, and those going to the teeth, are 
externally alike, and their contents are the same ; yet in the body 
no two substances differ more than medullary tnatter and enamel. 
What a display of Divine Wisdom is seen in the timely depo- 
sition of each tissue, and that in its exact quantity !” 
He afterwards observed, “ it is an interesting inquiry,, but 
somewhat difficult of solution, what is the agency by which this 
machinery is wrought upon ; or what are the powers which are 
brought to bear upon it so as to put it into motion, and to keep 
up that motion without ceasing, without weariness, without 
thought, for the most part without our consciousness ; and that 
every moment of our Jives, both during our waking and our 
sleeping hours?” 
After having referred to the various theories which are pro- 
mulgated respecting the manner in which the foetus in utero is 
supported, he preferred the following : — The arteries of the 
mother deposit in the cellular structure of the placenta a fluid 
(this, like all others, may be viewed as a secretion) differing in 
its properties from blood, and which is taken up by some of the 
veins of the foetus. This becomes mixed with that portion of 
the foetal blood which is returning by other veins ; these, taking 
their origin from some of the minute terminating capillaries of 
the arteries, and which anastomose to form larger ones and 
ramify over the membranes, but principally through the amnion, 
where their course is very tortuous. He was inclined to believe 
that here the watery or more liquid parts are separated, con- 
