68 



of nitric acid to the solution, wliieh turns yellow on 

 boiling and, after cooling, becomes orange on the addition 

 of ammonia). Millon's reagent, when added to the 

 original solution, gave a white precipitate, turning brick 

 red on boiling. The Biuret test also indicated proteid. 

 The concentrated solution is coagulated on heating. The 

 proteid as shown by Mitra belongs to the Globulin 

 class. 



With regard to the physiological projterties of the 

 style, the following must be noted. It disappears when 

 the animals are kept in sea water free from nutriment of 

 any kind. This has been shown to be also the case in 

 Anodon. After transit Mitra found that fifty might be 

 opened without showing any trace of the style, whereas 

 if placed in a fresh-water aquarium with plenty of food, 

 it was invariably present after an interval of a few hours. 

 Mitra also states that his mussels were not able to carry 

 on respiration and nutrition actively during the night, 

 owing to a leakage in the tank containing them, with the 

 result that the style was absent when mussels were 

 examined at eight o'clock in the morning, and the 

 digestive function was also in abeyance. 



Two or three hours afterwards the style would be 

 present. In the case of Pecten such rapid alterations 

 were not found, but specimens kept in a tank which was 

 simply aerated by an air ciirrent, and in water which was 

 practically free from food matter, were always found to 

 be without the styles. 



It seems that the presence of the crystalline style is 

 concerned with digestion, and it is interesting therefore 

 to find that it contains a digestive ferment. 



To test the action a solution of several styles was 

 made up and allowed to act on a starch solution for some 

 hours, precautions having been taken, as a control, to 



