1728 J. M. PRIHGO 



olive-growing region is limited by the central mountain ranges already men- 

 tioned which cross the plateau from W. S. W. to E. N. E. and meet the Ibe- 

 rian Moimtains in the N. E. Beyond the latter range the north-eastern 

 olive-growing districts are found in the lower part of the basin of the River 

 Ebro and include the whole of the provinces of Navarre and Alva. In the 

 north-western provinces and on the plateau of Old Castille the olive is not 

 grown but it is thoroughly established in the basins of the Tagus, the Gua- 

 diana, the Guadalquiver, the Segura and the Ebro. 



The soils on which the oli\'e is grown vary greatly, as do the geological 

 formations from which these soils are derived. Most of the soils are formed 

 from the remains of Cretaceous and Jurassic strata, from the Silurian slates of 

 the Iberian Mountains and central ranges, from the Triassic sands and sand- 

 stones, and from the conglomerates, sands, sandstones, and gypsum beds 

 of the Miocene which occur in the province of Alcaria and on the low plains 

 of Aragon and South Castille (La Mancha). These olive-growing soils are 

 comparatively rare in the valleys ; the hilltops and slopes are the situations 

 in which they are characteristically found. It may briefly be stated that in 

 such situations the soils which are formed either in situ or from transported 

 and partially broken down materials of a pebbly and stony character, which 

 lack spring-water and usually contain a large proportion of calcium carbo- 

 nate are undoubtedly in a bad condition for the cultivation of cereals but 

 are well adapted to the growth of trees of the type of the olive. 



As the result of these geographical features the olive-growing districts 

 are found at altitudes above that of the irrigation canals and at present only 

 177 300 acres of olive groves are irrigated that is about 4.7 per cent of the 

 total area under olive trees. 



The provinces in which the tree is grown comprise not less than a third 

 of Spain, and in this wide-spread district it is natural that the growth and 

 yield of the tree should vary considerably. The changes in the environment 

 of the plant in this extensive and mountainous country are numerous and 

 have given rise to the many varieties known in Spain. 



The study of these varieties have been the object of man}' experimental 

 trials ; special mention should be made of the work carried out in Andalusia 

 by M. RojAS Clement y Martinez Rohles and of that of Dr. Colmeiro 

 who has lateh^ collected eighty varieties- of which pictures are to be seen in 

 the nurser}' of the Botanical Garden Madrid. 



Chief varieties grown in Spain. 



0. europea pomifonnis Clem. (" 01i\o nianzanillo ")•— The tree is well de- 

 veloped, the branches are long with plentiful shoots and the leaves are large. 

 The fruit is symmetrical and almost splierical and of a light purple colour 

 when ripe ; it is largely used in tanning and gives an excellent oil. This 

 variety is cultivated in almost all the olive-growing provinces on account 

 of its excellent yield, in spite of the fact that the yield is in-egular from 

 one year to another (vecera) and that it requires to some extent special 

 soil conditions. 



