On the Juice of the Pseudotrunk of Musa 

 Basjoo, Sieb., in Winter-time. 



BY 



S. Sawa. 



The banana plants grown in central Japan lose their leaves 

 during the cold months and there remains only the pseudo- 

 trunk, 1 the interior of which seems to be sufficiently protected 

 against the freezing temperature of the cold nights by the 

 dead part surrounding it. This inner portion is subjected to a 

 period of rest for about four months. It seemed to me of some 

 interest to ascertain whether during this time any noticeable 

 decomposition of reserve protein matter took place, and for this 

 purpose nearly 3 kilos served for the preparation of the juice. 

 A portion of tissue was directly tested with a freshly prepared 

 solution of ferrous sulphate, but only a weak tannin reaction was 

 obtained and that only in the innermost parts. The expressed 

 juice, however, did not yield any decisive reaction at all. 

 Another portion of a fresh section was moistened with guaiacum 

 tincture and a very marked blue reaction was observed, showing 

 the presence of oxidase. A piece of the tissue was heated for a 

 few minutes at 8o°C. whereby the oxidase was killed, but the 

 reaction of peroxidase was now obtained in a marked degree 

 with a mixture of hydrogen peroxid and guaiacum tincture. As 

 to catalase, a slow development of oxygen was observed when 

 a piece of the tissue was placed in a diluted neutral solution of 

 hydrogen peroxid, while the filtered juice gave no reaction ; 

 hence only a- catalase was present in a small degree. 



In regard to the juice above mentioned I was surprised to 

 find that it did not show* any acid reaction at all, but that on 

 the contrary the reaction was slightly alkaline. Phospho- 



1 This pseudotrunk consists mainly of a series of rolled up leaves. 



