central position. Hence it is either this that is cut off, or into

this that the new shoot is inserted, when we wish either a new

branch or a new root to spring from it; which proves that the point of

origin in growth is intermediate between stem and root.

Likewise in sanguineous animals the heart is the first organ

developed; this is evident from what has been observed in those

cases where observation of their growth is possible. Hence in

bloodless animals also what corresponds to the heart must develop

first. We have already asserted in our treatise on The Parts of

Animals that it is from the heart that the veins issue, and that in

sanguineous animals the blood is the final nutriment from which the

members are formed. Hence it is clear that there is one function in

nutrition which the mouth has the faculty of performing, and a

different one appertaining to the stomach. But it is the heart that

has supreme control, exercising an additional and completing function.

Hence in sanguineous animals the source both of the sensitive and of

the nutritive soul must be in the heart, for the functions relative to

nutrition exercised by the other parts are ancillary to the activity

of the heart. It is the part of the dominating organ to achieve the

final result, as of the physician's efforts to be directed towards

health, and not to be occupied with subordinate offices.

Certainly, however, all saguineous animals have the supreme organ of

the sensefaculties in the heart, for it is here that we must look

for the common sensorium belonging to all the sense-organs. These in

two cases, taste and touch, can be clearly seen to extend to the

heart, and hence the others also must lead to it, for in it the

other organs may possibly initiate changes, whereas with the upper

region of the body taste and touch have no connexion. Apart from these

considerations, if the life is always located in this part,

evidently the principle of sensation must be situated there too, for

it is qua animal that an animal is said to be a living thing, and it

is called animal because endowed with sensation. Elsewhere in other