12 



only we must Iicre always remember, that the eye 

 never reaches to the smallest fibres, but to larger ones 

 made up of the smallest, and like to them in slender- 

 ness, placed together in a rectilineal course. That 

 these are not different from the smallest fibres, we are 

 persuaded by the most accurate microscopes of Muysc 

 and Lewenhoeck; by which the muscular fibres divided 

 even to the last, appear similar to the larger, till, at 

 length, they seem mere lines, like spiders threads. 



The second kind of fibres are those which are 

 conjoined with a breadth frequently larger than their 

 length. 



From what has been said, we may admire nature 

 no less for her wise eeconomy than simplicity, in thus 

 forming all that variety of parts we see in an animal, 

 from one simple mass of clay or slimy matter, com- 

 pounded of earth and glue 5 from whence the body 

 is not only augmented from a single point in the ovum 

 to its full growth and stature ; but like the timbers of 

 a ship, is also every day repaired during life, till at 

 length not two jots of the old or first materials remain. 

 This renovation of parts is made slower in some con. 

 stitutions, and in some organs than in others. How 

 quickly the animal humours, with the hair, nails, c. 

 are renewed^ every one knows : and we may venture 

 to say, that once in three years the change is universal^ 

 at the end of which time, though a man remains the 

 same identical person he is not the same matter. 



3. But we proceed from these simple fibres to the 

 next least compounded solid which they compose ; viz. 

 the cellular web-like substance. 



This is made up partly of the simple fibrils, and 

 partly by an infinite number of little plates or scales, 

 wnich, joined in various directions, intercept small 

 cells and web-like spaces ; and by extending round 

 every, even the least moving solid parts of the body, 

 conjoins them ail together in such a manner as not 

 only sustainsjbut allows them a free and ample motion. 



