rOUM OF WOOLLY FIBRE. 21 



benefit in this case to result from the removal of a ;?o?- 

 tton of each hair, which, if allowed to remain, would 

 lead to a sacrifice of the whole, by robbing the root of 

 a quantity of nutritious matter, which, owing to a dimi- 

 nution of reproductive power, it cobid ill afford. In 

 this way only can we account for the power which 

 shearing evinces, in putting a stop to the attempt some- 

 times made by nature to change the coverings of some 

 sheep. In the valley which separates the most eastern 

 chain of the Cordilleras from the central, the wool 

 grows upon the lambs in the same manner as in tempe- 

 rate climates, provided they are sheared so soon as it 

 has arrived at a certain thickness ; in which case the 

 wool grows again, preserving the same order. But, 

 if the period for denuding the animal be allowed to 

 pass, the wool detaches itself in flakes, leaving behind 

 a short, glossy, and compact hair, exactly resembling 

 that of the common goat in the same climate. 



(30.) Form of woolly fibre — The fibre of wool is 

 circular, differing in diameter in the various breeds, and 

 different parts of the same fleece. The following apro- 

 pos observations are from the article on the Sheep, in 

 the Library of Useful Knowledge : " The filaments of 

 white wool, when cleansed from grease, are semitrans- 

 parent ; their surface in some places is beautifully 

 polished, in others curiously encrusted, and they reflect 

 the rays of light in a very pleasing manner. When 

 viewed by the aid of a powerful achromatic microscope, 

 the central part of the fibre has a singularly glittering 

 appearance. Very irregularly placed minuter filaments 

 are sometimes seen branching from the main trunk, 

 like boughs from the principal stem. This exterior 



