402 Scientific Proceeiiinas. Roijal Dublin Sociei//. 



It may be added that in Bihar Indigo/era arrecta grows before the first 

 cutting to about four feet. The reaction is about pH 8'7 or over, and 

 available phosphates are low in many places in the calcareous silt. In parts 

 of Assam, when grown on certain tea gardens with an open sandy soil and an 

 abundance of available phosphate, the indigo grows luxuriantly, reaching ten 

 feet before the first cutting, and twelve to fifteen in a year. The soil reaction 

 is about pH 5'4-6'2, which favours the liberation of phosphate. It is of 

 importance to note that the sub-soii was very well aerated, being a coarse 

 sand in some cases. This means that iron salts must have existed largely in 

 the ferric condition, and that toxic aluminium salts must have been absent or 

 only present in minute amounts. With an equally acid clay soil their 

 concentration would probably have been greater. 



