210 PHYSIOLOGY. 



modern anatomists, that the solid parts consist entirely of a cel- 

 lular texture, of various density in the different parts ; and, in- 

 deed, the structure of the greatest part of the solids is evidently 

 of this kind. But, at the same time, it is also true, that a 

 fibrous structure is to be observed almost everywhere in the 

 body. It appears in the medullary substance of the brain and 

 nerves, in the muscles and tendons, in the arteries, in the ex- 

 cretories of the glands, in the lymphatic vessels, in the aliment- 

 ary canal, in the uterus and bladder of urine, in the ligaments, 

 in most membranes, and it is to be seen in those membranes 

 which are afterwards changed into bones, especially whilst this 

 change is going on. 



CCXCII. From this view of the universality of a fibrous 

 structure in animal bodies, we are disposed to believe, that these 

 fibres are the fundamental part of animal solids, that they are 

 the primordial staminal part of animal bodies, and that the cel- 

 lular texture is, for the most part, an accretion formed upon 

 these fibres. 



The consideration of the structure and growth of vegetables 

 seems to illustrate and confirm this opinion. 



CCXCIII. At the same time, from the fibrous parts 

 (CCXCI.) being evidently, in most instances, parts of the 

 nervous system, and from the gradual formation of the foetus, 

 in which the nervous system is first formed, we think it pro- 

 bable, that the whole of the fibres in the different parts of the 

 body, are a continuation of the nerves ; and this again will lead 

 to the conclusion, that the nourishment of the soft and homo- 

 geneous solid everywhere is conveyed to it by the nerves. 



CCXCIV. This supposes also, what is otherwise probable, 

 that the cortical part of the brain, or common origin of the 

 nerves, is a secretory organ, in which the gluten of the blood, 

 being freed from all saline matter before adhering to it, becomes 

 fit for the nourishment of the solids, and being poured in a suf- 

 ficiently diluted state upon the organ of the nerves, it is filtrat- 

 ed along the fibres of these, and is thus conveyed to every stam- 

 inal fibre of the system. We suppose, at the same time, that 

 the medullary, or what may be called the solid matter of the 

 nerves, is in the living body constantly accompanied with a sub- 

 tile elastic fluid, which fits them for being the organs of sense 



