Naturalisation in Extra-Tropical Countries. 543 



Palestine, Petali, Volo, Greek Wheat from Atlanti, Forelle ; 

 they all belong to the type, T. durum, and are remarkable for 

 their rigid solid stems and for their hard grains, rich in gluten, 

 and all requiring a warm clime. Change of seed-grains, even 

 of the same variety, from the most favorable localities, is always 

 desirable ; also avoidance of unbroken continuity of wheat-fields 

 over wide stretches of country, further rotative alterations or 

 periodic changes of crop, deep subsoil-ploughing, dressing with 

 crude salt. Such precautions are all the more necessary in 

 unusually wet seasons. 



Among the conditions for rendering Wheat-crops in a large measure 

 safe against rust-fungs are prominent : thorough drainage of the field, 

 sufficiency of potash, lime and phosphoric acid in the soil, choice of 

 varieties of least sappy constitution and of early maturation, frequent 

 renewal of seed-grain of rust-resisting varieties from their original 

 locations ; early sowing, and this not too close, suppression of all 

 kinds of grasses and weeds on the field and in its vicinity, selection 

 of whatever manures to be applied entirely free of rust, immediate 

 cutting of any affected portion of the crop, supervision strictly 

 exercised by public officials ; these measures to be connectedly 

 enjoined. Soil, so strongly pervaded by chloride of sodium, as 

 barely to be yet capable of producing ordinary grasses, seems also to 

 give wheat free of rust. Dr. Plowright recommends against smut 

 immersions of the seed-grain in water heated to 132 F. 



Tropaeolum majus. Linn. 



Peru. This showy perennial climber passes with impropriety 

 under the name of Nasturtium. The herbage and flowers serve as 

 cress, and are also considered antiscorbutic. The plant can be grown 

 in Norway northward to lat. 70 22' [Schuebeler]. Has some in- 

 secticidal value, and it is even said, that when planted around apple 

 trees, it will rid them finally of the woolly Aphis. Well suited to 

 conceal tubs in which ferntrees are grown. A smaller species, T. 

 minus, L., from Peru, can likewise be chosen for a cress-salad ; both 

 besides furnish in their flower-buds and young fruits a substitute for 

 capers. A volatile oil of burning taste can be distilled from the 

 foliage of both, and this is more acrid even than the distilled oil of 

 mustard-seeds. In colder countries these plants are only of one 

 year's duration. Numerous other species, all highly ornamental, 

 occur in South-America and some few also in Mexico. The seeds 

 will keep for several years. 



Tropseolum sessilifolrnm, Pceppig. 



Chili. Among the species of this genus one of the most eligible 

 for its tubers, which can be consumed even in a raw state, and are 

 larger than those of most other Tropaeolums, while the stems are 

 short and procumbent [Prof. PhilippiJ. 



