J'HYSIOLOGY OF THE INVERTEBRATA. 103 



The secretioii of the so-called liver of Carciiuis does not 

 •contain glycocholic and taurocholic acids, or glycogen. 



By using the methods of M. Zaleski* for ascertaining the 

 presence of ferrous, ferric, and ferrosoferric compounds in a 

 true liver, the author of the present volume could not detect 

 the presence of iron in the organ or its secretion. 



From the above reactions the conclusion to be drawn is, 

 that this bilobed organ is essentially paucreatic in function.! 



The Mackoura. 



The general details of the alimentary canal of ^Istecits have 

 been described in the last chapter. The principal organs are 

 the stomach and the " liver." 



The gastric juice of the crayfish has recently been investi- 

 gated by M. Stamati.J By means of a gastric fistula, the 

 gastric juice can be easily collected from the crayfish. This 

 secretion is of a yellowish colour, somewhat opalescent, and 

 alkaline to test-papers. It digests fibrin, rapidly forming 

 peptones which give the ordinary reactions : it also transforms 

 starch into glucose. It appears also that fats are emulsified 

 and fatty acids liberated. This so-called gastric juice of M, 

 Stamati was in fact nothing more than the secretion of the 

 " liver," which pours its secretion into the anterior part o£ 

 the intestine, and no doubt finds its way into the pyloric 

 portion of the crayfish's stomach. After the stomach of 

 Astacus has been thoroughly washed oat with water, an 

 extract of the organ does not digest fibrin, nor does it act upon 

 starch. This proves that Stamati's gastric juice was in reality 

 the secretion of the " liver." 



The so-called liver of Astacus fluviatUis has been proved 

 by the author § to be pancreatic in function. Its secretion 



* Zeitschrift fiir Physwhcjuche Chemie, vol. 10, pp. 4S3-502- 

 t Dr. A. B. Grifl5ths' paper in Proc. Boy. Soc. Edin., vol. 16, p. 178. 

 X Comptes Bendus de la Sodili Biologique, [2], t. S, p. 16. j, 

 § Griffiths' paper in Proc. Boy. JSoc. Edin., vol. 14, p. 237. 



