THE JOURNAL OF PHARMACOLOGY. 



237 



ingly thin. But few millimeters above the base some single medulla isles 

 will be found, consisting of simple longitudinal cells ; the medullary cylin- 

 der will follow, which soon becomes very broad. The greatest thickness, 

 about 200 p., will be found i cm. below the fine tip. At the thickest 

 portion the fibrous layer will be but 13 ij. in thickness and the thick-walled 

 medulla cells will be in ten rows. They extend transversely. 



5. Hairs of Cows and Calves. 



These will always be incinerated, that is, treated with slaked lime, pull 

 hairs. For this reason the hair bulbs will usually be 

 present. 



Calf hairs consist of three sorts of hairs, with some 

 transitional forms (Fig. 11). 



(a) The thick, stiff grannen hairs, 5 to 10 cm. in length, 

 have a long and narrow bulb. The throat of the hair is 

 equally long and reveals a one-rowed medullary cylinder, 

 as well as medulla isles. The epidermal scales are very 

 thin here, broader than high, notched and imbricated. 

 The thickness of the throat is 12011.. The hairs increase 

 slowly in thickness (to about 130//), the medullary cylin- 

 der becomes broad and consists of narrow imbricated ele- 

 ments. The fibrous layer is finely striate. The epiderm 

 can be seen with difficulty only, and has the same struc- 

 ture as at throat. The edge of fiber is smooth. The 

 medulla cells are very thin-walled, with a large amount of 

 finely granular contents. Towards the colorless tips o^ 

 the hairs distinct fiber fissures appear. The epiderm 

 remains very thin, closely scaled and finely toothed. 

 Shortly before the tip the medullary cylinder disappears, pj^ „ Themid- 

 the fissures become more distinct, whereas the epiderm die of a grannen hair 



J . from calf. It shows 



undergoes no change. ^^^ thin-waiied med- 



Their difference from the goat grannen hairs is remark- uiiary ceiis which 



able inasmuch as the medulla cells are in but one row, °^^ ^, ^ '^^.^ '- ^-^ 



' coarsely striped n- 



very thin-walled and the medulla often is in partitions brous layer/, and the 

 caused by tearing, or larger round lumens filled with air '^^^[o^ imbricated 



■^ ° ° epidermal scales. 



are formed. The cells are always rich in fine granular 350. 

 contents. 



( To be continued.) 



