26 HOPS. 



the trichomatic cuticular structures principally occurring on 

 the hop plant are as follows : — 



A. Pointed Hairs. 

 I. With a single terminal point, 

 l! Hairs filled with air. 



Unicellular, undivided hairs. 

 a Long, soft hairs. 

 $ Stiff, brush-like, and thorny hairs. 

 2. Hairs containing a cystolith. 



II. Hairs with two lateral points (climbing hairs). 



B. The outer ends (border cells of the hairs) are rounded. 

 I. Unicellular trichomes. 



1. Stigma papillse. 



2. Boot hairs. 



II. Multicellular glandular hairs. 



1. The glandular cells form a head. 



2. The glandular cells form a plane surface, which is either — 



(a) Disc-shaped, or 



(b) Cupped (Lupulin granules). 



Between the bristles and cystolithic hairs on the one hand, 

 the bristles and climbing hairs on the other, and again 

 between the typical forms of glandular hairs, are many inter- 

 mediate modifications. 



When the stage of ripeness is attained, many of the 

 lupulin granules become detached from their support, and 

 adhere to the spindle or spike of the cone so as to produce 

 the impression that this is their original site of development. 

 Hop-growers and brewers term the lupulin granules " hop 

 flour" or "hop meal"; and the quality and value of hops 

 are principally dependent on the amount of this lupulin and 

 on the aroma it imparts. The quantity present varies with 

 the kind of hop, the soil, the climate, conditions of nutrition, 

 and the year. 



Fresh-gathered, good, sound hops possess an agreeable, 

 though strongly narcotic, aroma, whilst inferior sorts exhibit 

 a characteristic odour of garlic. 



