•PHYSIOLOGY OF THE INVERTEBRATA. 105 



the " liver " pigments of certain genera of the Mollusca, as 

 well as from a large number of other Invertebrates. Among 

 the Mollusca experimented on were — Mytibis, Ostrea, Ano-^ 

 donta, Cardium, ITnio, Octopus, £uccinum, Patella, Helix, and 

 Linmx. In some Molluscs- — as Patella — the "liver" contains 

 enterohasmatin besides enterochlorophyll. It might be 

 suggested in reference to the discovery by Fredericq of 

 glycogen (CgH^oOj) in the "liver" of Mija that it was pro- 

 duced by the enterochlorophyll present in the organ ; as 

 enterochlorophyll is allied to chlorophyll. But MacMunn 

 (loc. cit., p. 257) states that he has made "various sections of 

 Invertebrate ' livers ' obtained from animals feeding and fast- 

 ing, but never obtained a trace of starch {G^^fi^ or cellulose 

 with iodine in iodide of potassium, Schulze's fluid, or with 

 iodine and sulphuric acid. These experiments were made 

 on the 'livers' of Helix aspersa, Anodonta ei/gnca. Patella 

 vulgata, Ostrea eclidis, Mytihis cdulis, Astacus flicriatilis, the 

 caeca of star fishes, &c. The precautions recommended by 

 Geddes* of previously digesting the tissues in alcohol, and in 

 caustic potash, and neutralising with acetic acid, having been 

 adopted in each case." 



It appears that the " enterochlorophyll occurs dissolved in 

 oil globules, also in granular form, and sometimes dissolved 

 in the protoplasm of the secreting cells of the ' liver.' " The 

 probable function of this and other pigments will be alluded 

 to in a subsequent chapter. 



The Gasteeopoda. 



The secretion of the salivary glands of Hcli.r aspersa has 

 been examined by the author.f It contains a ferment which 

 converts starch into glucose. The ferric chloride test failed 

 to show the presence of sulphocyanates. The mineral ingre- 

 dients found were calcium and chlorine ; but no phosphates 



* Proc. Boy. Soe. Edin., vol. 1 1, p. 377- 

 t Ihul, vol. 14, p. 235. . 



