glands, placed at the root of the tongue, which sup- 

 ply an humour, to keep the mouth and the tongue 

 6ntinually moist. 



The Wind pipe is wonderful in Hs conformation : 

 because continual respiration is necessary, it is made 

 with annular cartilages, to keep it constantly open, 

 that its sidles may not fall together : and lest, when we 

 swallow, any particle of food should fall in, which 

 might cause convulsions, or even death, it has a strong 

 shutter, or lid, called the epiglottis, which, whenever 

 we eat or drink, falls down of itself, and covers it 

 close, so that no crumb or drop can enter. It is for 

 the more convenient bending of our necks, that the 

 wind. pipe is not made of one entire continued carti- 

 lage, but of many circular ones. 



What is farther remarkable in these cartilages is, 

 that all the way where they are contiguous to the gul- 

 let, they are membranous, to give an easy passage to 

 the food : but after that, they are, some completely 

 round, some triangular. Another thing observable is, 

 in the wind. pipe, the cartilages run parallel to each 

 other: but, in the lungs, the lower parts of the siu 

 perior cartilages receive the upper parts of the infe- 

 rior : hereby enabling them to contract themselves in 

 expiration^ arid to dilate in inspiration. 



34. The Hairs are all hollow. The root of each hair 

 is fixed in a mucous globule, of an oval figure, which 

 often adheres to it, when it is pulled up by the root* 

 They are jointed like a reed or cane, and shoot out 

 into smajl branches. They serve not only for a co- 

 vering, but also for the excretion and expiration of ap 

 oily matter. 



Every hair does properly live, and receive nourish* 

 ment like the other parts. The roots do not turn 

 white or grey in age, any sooner than the extremes. 

 But the whole of each hair changes colour at once. Or 

 (to speak more properly) the hairs of another colour 

 fall off, and white ones grow in their place. 



But extreme fear may turn the hair gr'ey, or e?en 

 D 3 



