BUTLER AND HAFIZ. 177 



Bombay Punclia cane wliich, when introduced at Samalkota, went 

 out from disease in the first season, though the parent stock 

 is little subject to red rot. Kulkarni' also notes the gradual 

 deterioration of thick canes in parts of Bombay,, and West Indian 

 Hterature is full of references to the breaking down in health of the 

 Bourbon cane, once widely grown, and this breaking down seems 

 to have gone on more rapidly in some locahties than in others. 



These experiences with sugarcane are by no means unique 

 amongst plants ordinarily propagated in a vegetative manner, that 

 is by tubers, cuttings and the like. In Ireland the "Champion" 

 potato was largely cultivated for many years, on account of its 

 resistance to potato blight, but it has lost its resisting powers and 

 been replaced by newer " seedling " varieties. Several similar 

 cases are known, and the phenomenon is of considerable scientific 

 interest.^ Such progressive deterioration is in many cases 

 apparently innate and has been likened to senescence, being capable 

 of being checked when a new generation is started by sexual 

 reproduction {e.g., by raising from seed). But it can be hastened 

 by exposure to unfavourable conditions or, on the other hand, be 

 postponed by profound change in the environment. Barber states'' 

 that the surest way to induce red rot in cane to make its appearance 

 is to plant the canes in a water-logged site. Harrison, in British 

 Guiana, considers that the susceptibility of certain kinds of plants 

 foi" instance, the Bourbon cane, to fungus attacks is due in part at 

 least to defective soil conditions.' Such statements can be multi- 

 ]:)lied and must, we think, indicate a real phenomenon. In the 

 opposite direction are such cases as that recorded by Calkins,'' where 

 a constantly changing culture medium was found to have the effect 



' Kiilkanii, ( !. S. Proliininary fstiidy of the rod rot of sugarcane in tlie Bombay Prosidcncy. 

 Department of Agriculture, IJomlay, Bull. No. 44, 101 J. 



2 e. f. Hartog, ^f. Prolijems of Life and neprodiict ion. Progressive Science Series, 

 1!)13, p. 19. 



3 Barber, C. A. The Samalkota Sugarcane Farm, .\gric. Journ. of India, I, lOOti, 

 p. 45. 



* Harrison, J. B. Varieties of Sugarcane and Manurial experiments in British Guiana. 

 West Indian Bulletin, IX, 1000, p. .30. 



6 Calkins, Gary N. Protozoology, 11)10, p. 109. 



