ON THE CAUSES OF ORGAHIZ ATlON, 359 



bloodvessels approaching the base should have 

 exactly the usual characters of those that are des- 

 tined to nourish a regularly proportioned organ. 



But though such an hypothesis may illustrate 

 the case of which he is treating, it will not ex- 

 plain how the other fetuses to which he alludes, are 

 formed, without the head,-^some without the 

 head and the neck, — some without the head, the 

 neck, and the shoulder s,-^atid some without the 

 abdominal viscera. It is not insinuated, nor is it 

 believed, that the parts wanting in these fetuses 

 had ever existed ; and it is therefore admitted, 

 that a great number of the organs may be formed 

 without the aid or co-operation of those that are 

 considered as of principal importance. 



Hence, the hypothesis, that growth and vitality 

 in all circumstances, are necessarily dependent on 

 the action of these organs, is proved to be false, 

 and to be founded, like many other physiological 

 deductions, on what Bacon calls Experientia vul*- 

 garis,^2i kind of experience that but rarely leads 

 to certain conclusions. 



It is true, that in most animals, if the head, 

 the brain, or abdominal viscera were to be remov- 

 ed, the consequence would be the immediate death 

 of all the other parts. Nay, from the connection, 

 the mutual dependence, and the powerful sym- 

 pathy occasionally subsisting among the different 

 parts of the system, it is even true, that a slight 

 injury inflicted on parts which usually arc con- 

 M m 4 



