Naturalisation in Extra-Tropical Countries. 335 



years. Truncheons or estacas may be from one to many feet long 

 and from one to many inches thick ; they are placed in the ground 

 horizontally. Some Olive-plantations at Grasse are worth from 200 

 to 250 per acre. For many details the tract on the " Culture of 

 Olive and its Utilisation," issued in Melbourne by the Rev. Dr. 

 Bleasdale, should be consulted, as it rests largely on its author's 

 observations during a long stay in Portugal ; also the essay of. Sir 

 Samuel Davenport in Adelaide, the treatise issued by Capt. Ellwood 

 Cooper in San Francisco, the remarks by Prof. Hilgard in the 

 Bulletin No. 85 and 92 of the Agricultural Experimental Station, 

 Berkeley, California, February, 1890, and March, 1891, further the 

 notes by Mr. J. L. Thompson, of the Dookie Agricultural College, 

 in the "Leader/' June, 1890, as well as Mr. B. M. Lelong's observa- 

 tions in the "Victorian Farmers' Gazette/' February and April, 1889. 

 The olive will resist considerable frost (5 F.) for a short time, pro- 

 vided that the thawing takes place under fogs or mild rain (or 

 perhaps under a dense smoke). It requires about one-third more 

 annual warmth than the vine for ripening its fruit. The Olive-zones of 

 South-Europe and North- Africa are between 18 and 44 north 

 latitude. An elevation of about 550 feet corresponds in Spain, as far 

 as this culture is concerned, to one degree further north. Mr. Thozet 

 reared already good varieties many years ago in the lowlands just 

 within the tropics of Eastern Australia, where they bear freely and 

 produce an excellent oil. Olives do not grow well on granitic soil, 

 nor bear well on light soil. The fruit produced on limestone-forma- 

 tions is of the best quality. Gypsum promotes the growth of the 

 tree. An equable temperature serves best ; hence exposure to pre- 

 vailing strong winds is to be avoided. The winter-temperature should 

 not fall below 19 F. The quantity of oil in the fruit varies from 10 

 to 20 per cent.; sometimes it even exceeds the latter proportion. In 

 Provence on an average 24 Ibs. of olive-oil are consumed by each 

 individual of the population annually ; in Andalusia, about 30 Ibs. 

 G. Don mentions an aged tree near Gerecomio to have provided olives 

 for 240 quarts of oil in one year. For obtaining the largest quantity 

 of oil the fruit must be completely ripe. Hand-picked olives give the 

 purest oil. Knocking the fruit from the branches with sticks injures 

 the tree and lessens its productiveness the next year. No heat 

 should be used in the extracting and purifying of the oil. To 

 preserve the oil well, it should not be exposed to light. Spain alone 

 produces about 250,000,000 Ibs. of olive-oil a year. The quantity of 

 olives raised in France during 1890 was estimated at 134,000 tons, 

 valued at 1,080,000 [Sahut,from "Bull, du Minist^re d 'Agriculture"]. 

 Tunis possesses about 10,000,000 Olive-trees, supposed to yield a pro- 

 duce worth 1,000,000 sterling. The yield of the crop in Spain is 

 estimated at 9,000,000 sterling annually ; that of Italy 8,000,000. 

 The imports of olive-oil into the United Kingdom in 1884 amounted 

 to 17,000 tons, valued at 715,000 ; in 1889 the quantity was 22,882 

 tons, valued at 817,000. The import into Victoria during 1887 was 

 estimated at 10,919. 



