Naturalisation in Extra- Tropical Countries. 493 



cutting of any affected position 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, Linne. 



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 insecticidal value, and it is even said, that when planted 

 around apple trees, it will rid them finally of the woolly Aphis. 

 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. 



Tropaeolum sessilifclium, 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 Tropseolums, while the stems are 

 short and procumbent [Prof. Philippi]. 



Peru and Bolivia, up to the higher mountain-regions. The 

 tuberous root serves as an esculent ; some frost improves it. 



Tropliis Americana, Linne. 



West-Indian Archipelagus. The foliage of this milky tree has 

 been recommended as food for the silk-insect. In Cuba and 

 Jamaica it is used as provender for cattle and sheep. 



Tuber aestivum, Micheli. 



Middle and Southern Europe. The truffle most frequent in the 

 markets of England. The White British Truffle, Chairomyces 

 meandriformis, though large, is valued less. In the Department 

 Vaucluse alone about 60,000 Ibs. of truffles are collected annually, 

 at a value of about 4,000. Many other kinds of truffles are in 

 use. The Australian truffle, Mylitta Australis (Berkeley) or Notio- 

 hydiium Australe, sometimes attains the size of the cocoa-nut, and 

 is also a fair esculent. It seems quite feasible, to naturalise the 

 best edible fungs of these and other genera, although such may not 



