2o8 THE JOURNAL OF PHARMACOLOGY. 



We will first observe those wools which consist entirely of wool hairs. 



Meri7io Wool (Fig. i) and its Allied Species. — These are characterized 

 in the first place by their fineness (12 to 37 i>- in thickness) ; secondly by 

 their distinctly imbricated scales, of which there is but one, or two, in 

 each cross-section of the hair, seldom more, and they are therefore cylin- 

 drical or semi-cylindrical. 



Medulla is always absent. Medullary isles which may be present must 

 be regarded as errors. 



The fibrous sheath is firm, well developed and distinctly longitudinally 

 striate. The scales are perceptibly thickened at the fore edge. 



The wool always appears distinctly or conspicuously indented or ser- 

 rate. The scales seem to be tucked like paper bags one in another, es- 

 pecially noticeable in the case of the finer sorts. The front edge of the 

 scales is slightly sinuous, more or less transverse. The free parts of the 

 scales are often as wide as the fiber, so that the length of the free scale 

 edges is, on the average, as great as the breadth of the entire fiber. Fig. 

 I can serve as a type of a fine thread of one of the finest Merino drawn 

 wools. 



Very fine wools are obtained from the breed derived from the Rambou- 



illet stock. 



This cultivated breed was derived from the Merinos, therefore the mi- 

 croscopical characters of the Rambouillet wools are almost identical to 

 those obtained from the Spanish breed. A sort that was minutely exam- 

 ined consisted of normally sinuous wool hairs 13 to 34 11 in thickness ; the 

 scales were entirely or half cylindrical, not as high as those of the real 

 Merino, cut more on the slant, coarser ; the outer edge frequently showed 

 a large dull or pointed projecting tooth, which occurs less frequently 

 in the Merino. The fibrous sheath is very coarsely striate and the hair, 

 which is always without a medulla, is distinctly dentate at the sides (Fig. 

 2). The wools of the pure cultivated Saxon Electoral stock and the 

 Australian Imperial, which are descended from the Escurial breed of 

 Spain, are, on the whole, finer than the Spanish wools and otherwise not 

 different microscopically from the Merino wools. 



The finest and finest curled wools are those obtained from the Saxon 

 Electorals. 



Concerning sheep wools which consist only of grannen hairs, to this 

 class belong the English Leicester and New Leicester breeds (Fig. 3). 



These are fine (30 to 60 ft in thickness), glossy wools with marked but 

 coarse quarta curlings and generally long (10 to 20 cm.). The hairs are 

 all of about the same breadth. On the extreme end about 30 p- and further 

 down to about 60 p-. The outer 3 or 4 cm. of the length are always with- 

 out a medulla, with distinct thick edged echinated and imbricated scales. 

 Further down single narrow and elongated medullary cells appear here 



