136 EXPLOITATION OF PLANTS 
ing; but that the chief factor is the special jat (variety) 
of plant cultivated—a jat unknown in India or Ceylon, 
and calling for such cultural treatment as renders its 
cultivation in those countries impossible. That the 
natives themselves are fully aware of the importance 
of the jat, and of the necessity for keeping it true 
to type, is evidenced by the fact that, while in every 
other tea-growing country the bushes are normally 
propagated by seed (with the attendant possibilities of 
variation, hybridisation, etc.), in Formosa all but the 
inferior oolong plants are propagated vegetatively, by 
layering. 
The importance of the jat as a factor affecting the 
quality of the Formosan teas is.a reminder that it would 
be misleading to suppose that the processes of manu- 
facture alone influence the character of the resulting 
tea. The case has been stated thus: “‘ A correctly 
grown tea plant provides the possibilities of a good tea ; 
it is the aim of good methods of manufacture to realise 
these possibilities to the fullest extent.’’ Apart from 
their effect upon yield of leaf per acre, it is well known 
that differences of jat, rainfall, elevation; differences 
of soil, manuring, and even type of pruning have their 
effect on the quality of the final product, and are taken 
into the fullest consideration by the practical planter. 
Brick teas— These famous teas form an important item 
in the Chinese trade, and are of two distinct kinds, 
differing in methods of manufacture, physical characters, 
and manner of domestic use. The first class comprises 
the brick (and tablet) teas destined for the Russian 
markets. These teas are no more than the dust and 
siftings of ordinary black and green teas compressed 
