94 THURLOW C. NELSON 



The alcohol precipitate from an aqueous solution of styles 

 was kept under alcohol for several months, and finding that the 

 ferment power of this precipitate became increasingly less as 

 it became more insoluble in water, Mitra concluded that the 

 enzyme and protein of the style were identical. 



Von Furth, reviewing part of the literature, believed that it 

 was more reasonable to suppose, with Coupin, that from the 

 colloidal nature of the style it was really a mixture of enzyme 

 and albuminoid material, rather than a solid mass of enzyme. 



Van Rynberk ('08) repeated the experiments of Coupin and 

 Mitra, and extended them to cover a comparison of the digestive 

 activity of the style and the hepatopancreas on fats, proteins, 

 and carbohydrates. This author found no action upon fats or 

 proteids, nor upon cellulose, though starch was quickly digested, 

 and raw sugar inverted by the enzymes present, in both the 

 style and hepatopancreas. 



My own investigations, as far as carried out, confirm those of 

 Coupin and van Rynberk, and differ from those of Mitra only in 

 so far as he regarded the style as exclusively a mass of enzyme. 

 When digestion is proceeding slowly in Anodonta, as during the 

 winter, the stomach contains a large amount of brown, ropy 

 fluid, resulting partly from the dissolution of the style, and 

 partly from secretions from the hepatopancreas. About 0.5 cc. 

 of this liquid was drawn off and mixed with an equal volume of 

 a 0.5 per cent starch solution, and the mixture placed at 32 °C. 

 In an hour the starch was completely digested. An extract of 

 the hepatopancreas showed a similar activity, though the action 

 was not nearly as rapid. 



Mitra extracted the mid intestine and found a very faint amyl- 

 olytic action of the filtrate. Van Rynberk repeated the work, 

 but failed to confirm his result. 



Since the secreting glands of the typhlosoles are all unicellu- 

 lar, it is evident that little enzyme could be stored in them. 

 The following experiment was designed to avoid this possible 

 source of error. The typhlosoles, together with the wall of the 

 style sac, were carefully removed from an adult Anodonta. That 

 part near the hepatopancreas was discarded, and the rest, after 



