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Carbohydrate.
Using Pflueger's method of estimation, we obtained the following figures for the glycogen percentage of freshly treated Haliotis iris:—
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| Sample. | Part. | Weight in Grammes. | Amount used (Grammes). | Percentage of Glycogen. |
|---|---|---|---|---|
| I | Muscle | 156 | 100 | 1.20 |
| Viscera | 104 | 104 | 0.54 | |
| II | Muscle | 160 | 100 | 2.01 |
| Viscera | 135 | 125 | 0.50 |
An attempt was made to obtain a clear watery extract for estimation of glucose, so that we might find the total percentage of carbohydrate present, but in spite of various devices the filtration proved so slow that the material began to decompose and had to be abandoned. The cause of
![Thumbnail: [Volume 55, 1924 page 379]](/journals/rsnz/images/rsnz_55/thumbnails/rsnz_55_00_0457_0379_ac_02.gif)
the slow filtration was undoubtedly the large amount of slimy mucus that was present. Glucose could easily be detected in the crude extract.
The glycogen from paua “muscle” gave the usual qualitative tests, and on hydrolysis yielded glucose—at least, so far as we could judge from the fermentation and phenyl-hydrazine tests—but the glycogen from the “viscera” did not react in a typical way. The result of its hydrolysis did not reduce so readily as glucose solutions do, and in one test it failed to ferment with yeast. Unfortunately the time at our disposal did not allow of further investigation while the material was fresh. The origin of the glycogen found in marine shell-fish is worth investigating; for, unlike the terrestrial plants which contain starch, the seaweeds on which the paua, &c., feed contain chiefly pentosanes, methyl pentoses, and pentoses; and the transformation of these into glycogen does not occur readily, if at all, in the vertebrates.
In carrying out Pflueger's method for glycogen (heating for several hours with 30 per cent. KOH) it was found that the glycogen, when precipitated with alcohol, carried down with it a certain amount of greasy material which retarded the filtration. This was almost certainly some of the unsaponifiable fatty matter which had withstood the action of the alkali.