4Q 



1896.] ^^ Ll'epper. 



planks ; but this twisting can be lessened in many cases by growing 

 the trees in close and extensive plantations, which gives most of them 

 proper protection against the winds. Yet another objection is that euca- 

 Ij'pti will not thrive generally when iutergrown with other trees, and will 

 interfere with the other trees and even kill them off; or, more rarely in 

 these colonies, that they will be injured by the other trees. Both of these 

 facts can be prevented by leaving sufficient space between eucalypti and 

 the other trees. 



The principal and insuperable objection to eucalypti requires also but a 

 simple mention here : there is no money to be made from them, or, at 

 least, such is the experience of the growers until now, the trees having 

 been introduced into Algeria and Tunisia more than a quarter of a cen- 

 tury ago. Those who recommended their being grown by others for a 

 large profit have benefited by being prematurely rewarded by the govern- 

 ment for their zeal. 



Alas ! that favorable prophecies, with all the calculations to support 

 them, should have proved fallacious. 



IV. 



Species and Varieties of Eucalypti Most Serviceable ix Tunisia 



AND Algeria. 



Among the very numerous species and varieties of eucalypti, our choice 

 is founded on the recent study and actual knowledge of the trees. Eu. 

 globulus (blue gum) grows well enough in generally dry soils,* and yet is 

 especially suited to damp subsoils; its leaves and fruit are rich in essential 

 oil and it is abundant in its indigenous soil, Australia. We owe the fact 

 of its being the first species introduced into northern Africa to these ad- 

 vantages, as mentioned in our second chapter ; also to the fact that there 

 was at the time a relative, if not absolute, ignorance of the merits of the 

 more valuable and equally hardy or even hardier species (which are 

 still not sufficiently known in these colonies). But its wood is inferior 

 for any purpose, as is fully stated elsewhere, and the red gums have been 

 generally preferred within the last few years. 



We refer at length in our last chapter to the many qualities of E2i. mar- 

 ginata, w^hich is as yet so extremely rare as to be scarcely noticeable in a 

 practical nomenclature of species found here. 



Among the most remarkable species of red gums grown here are Eu. 

 rostrata and Eu. resinifera, and numerous hybrids or crosses of these 

 species. The former, when extensively grown from the seed and planted 

 out, furnishes a good wood, withstands the dryness of the summer in the 

 interior, seems to be one of the most resistant of trees, and reproduces it- 

 self spontaneously in the coast region (where, probably, it will soon be- 



* Nevertheless it sometimes dies suddenly witliout apparent cause after attaining a 

 considerable size. 



PROC. AMER. PHILOS. SOC. XXXV. 150. G. printed JUNE 5, 1890. 



