i 4 6 SCIENCE PROGRESS 



and the stem. This region, later known as the "collet" or 

 neck, was, even after the time of Linnaeus, regarded with a 

 superstitious respect, as though here had been established some 

 special focus of vitality. 



Caesalpinus is, however, later on in this dissertation, quite 

 inconsistent with the notion of the localisation of the plant-soul, 

 for, although he has assigned it to the union of the root and 

 the stem, he is afterwards forced to admit that the vegetable 

 soul must be diffused through all the parts, even to the 

 extremities of the leaves, which, of course, are very much alive. 



Csesalpinus had only followed Aristotle in believing in a 

 plant-soul : his conception of plant-life is quite Aristotelian, 

 thus : " As the nature of plants possesses only that kind of soul 

 by which they are nourished, grow and produce their like, and 

 they are therefore without sensation and motion, in which the 

 nature of animals consists, plants have accordingly need of a 

 much smaller apparatus of organs than animals." 



The well-known man of science, the Burgundian Mariotte 

 (died 1684), in his Sur le Sujet des P/antes, declares that, as we 

 know nothing about the vegetable soul, the assumption of it 

 is not helpful in plant physiology. 



If we go far enough back in the history of thought about 

 the relations of the soul to a material substratum, we find that 

 the seat of the mental processes was not originally supposed 

 to be within the nervous system at all. The ancient Egyptians 

 regarded the soul as seated in the heart, as also did Aristotle 

 (b.c. 384-322), an idea by no means fantastic when we reflect 

 on the ease and certainty with which emotional states influence 

 the force and rate of the action of that organ. As late as the 

 time of the Neapolitan philosopher Vico (1678-1774) tms idea 

 was revived, Vico insisting, contrary to Descartes, that the mind 

 was in the heart and not in the head. 



Aristotle, in particular, referred to the brain as "cold and 

 bloodness," and imagined its function to be that of cooling 

 vapours from the heart. 



Another old Greek idea was that the mind or soul resided 

 in the diaphragm, a reference to which still lingers in our own 

 word phrensy (frenzy), which is derived from phren, the Greek 

 word for the diaphragm. " Phreno-pathia" is a now little-used 

 term for mental disease, and " phrenetic " means mentally ex- 

 citable, while " phrenitis " has actually become a synonym for 



