THE HOP PLANT. 43 



3. Compound cones — 



(a) Through the development of the primal branchlet of a 

 spicula of the first order into a latera,! spike bearing one or 

 more spiculae of the second order ; 



(b) Through the development of the primal branchlet of 

 such a spicula of the second order into a lateral spike bearing 

 a spicula of the third order, and so on ; 



(c) Through the development of terminal vegetative buds 

 on the axis of such spiculae of the secondary and tertiary- 

 orders. 



IV. The central floral axis of a spicula- twig may be only 

 imperfectly developed into blossom, but form instead a very 

 fine and extremely tender leaflet, which must be regarded as 

 the sheath of an abortive blossom. To this class belong also 

 the apparently petiolate leaflets occasionally put forth 

 laterally in perfect flowers. 



V. Other deviations, which in ,some part have been 

 already described, are produced by the development of other 

 parts of the cone which are normally undeveloped or even 

 absent entirely : — 



1. Elongations wherein the apex of the spike is subse- 

 quently prolonged and undergoes further growth (Fig. 17). 



2. Development of the otherwise rudimentary floral 

 leaves of a spicula into more or less perfect foliage leaves — 



(a) Foliations due to the development of perfect 

 (generally simple) leaves out of the leaflets on the spiculae. 

 There are various intermediate forms between the two. The 

 production of foliage leaves on the cone is indicative of 

 barrenness, such cones being, as a rule, destitute of lupulin 

 glands ; 



(b) A kind of bract may also develop on the base of the 

 floral leaf, so that such a spicula exhibits three bracts ; 



(c) Or, instead of the third bract being free, it may be 

 intergrown or fused with one of the true bracts. 



