138 A SPRIXG TOUR IX TORTUGAL. 



the same cause as that which produces an oasis in the 

 sterile desert. A trickling spring- bursting from the rock, 

 and conducted through the garden, is the secret which, 

 in this splendid climate, works wonders in the vegetable 

 world. And so we found tliroughout northern Portugal, 

 in the rich province of Minho, an abundance of water 

 was the true source of its fertility ; and as no district in 

 the country is so well furnished with brooks and streams, 

 so none other is so fruitful. Even the famous vines of 

 Traz-os-Montes, which notoriously can endure long con- 

 tinued drought, are at stated seasons carefully supplied 

 with water ; and, indeed I may close this botanical chapter 

 with the aphorism well known in the thirsty, Avater-loving, 

 water-drinking Peninsula, 'a perennial spring is the greatest 

 earthly gift which Grod bestows on man.' 



