OP NAIAS GRAMINEA^ VAR. DELILEI. 67 



regions of Asia, and probably in Japan. It does not occur 

 in Europe except as a colonist, it having been introduced 

 (according to the Italian botanists) with East-Indian rice, 

 into districts where that cereal is cultivated, as in the 

 plains of Lombardy and Venice ; the Italian localities are 

 given in Cesati^s 'Compendio della Flora Italiana,^ as 

 Alagna in Novara, Balzola between Vercelli and Casale, 

 Merlato near Milan, Upper Vercellese, Strasoldo nel Priuli 

 near Palmanavo. It has also been reported from the 

 extreme north-eastern portion of Austria; but it is not 

 native in any of its European stations, and it is an intro- 

 duction in Lancashire. It becomes, therefore, an inter- 

 esting question to account for its appearance in a country 

 which does not grow the rice which it consumes. 



XVIII. Its probable Source. 



When this plant was exhibited at the British Association 

 at Southport, in September 1883, I expressed the opinion 

 in the Biological Section that it had probably been intro- 

 duced into the Reddish locality with Egyptian cotton. 

 This class of cotton is not one of the staple articles of 

 consumption in the Stockport district, but there is one 

 mill on the banks of the canal (Houldsworth^s) which 

 consumes Egyptian cotton largely, and from it, if not from 

 others, the fruits of the Naias may have been transported 

 to the canal. Last autumn Mr. J. Cosmo Melvill and 

 myself carefully examined the large condensing-tank in 

 the yard of this mill, but we could not find a trace of the 

 plant; the water was of a high temperature, and little 

 vegetation was found in it, but its depth was beyond our 

 means of properly exploring it. 



Alire Raffenau Delile* gives an account of the culture 



* ' M^moire Bur les plantes qui croissent spontaii6inent en Egypte,' vol. ii. 

 pp. 16, 17. 



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