33 



of experiments carried out on Mytilus, from which it 

 appears that not only is the style absorbed during the 

 starvation of the animal by keeping it in filtered sea-water, 

 but it is formed anew on abundant food being supplied. 

 Haseloff inferred that the style "is the product of the 

 chemical transformation of the excess of food material 

 taken in by the animal, the change being effected by the 

 agency of the digestive ferments." More lately, Woodward* 

 working on the same mollusc, was able to confirm Haseloff' s 

 experiments. 



Barrois rejects the conclusion of Hazay and Haseloff, 

 basing his objections chiefly on the chemical composition 

 of the style which is very different from that of most reserve 

 food materials, and on the unusual form in which the 

 substance is stored up. In both these points it differs 

 notably from all undoubted physiological reserves. In 

 Helix poviatia, which undergoes a true hibernation, abun- 

 dant reserve food material is stored up in the liver in the 

 form of glycogen. This substance undergoes a gradual 

 change into sugar in the course of the hibernation period, 

 and ultimately disappears completely. Moreover, neither 

 in Mytilus nor in Cardium taken during all times in the 

 year was he able to observe any change in the volume of 

 the style. Specimens of Cardium were placed in filtered 

 sea-water and starved for eleven days. Only after the 

 eighth day was any diminution in volume observed, and in 

 general complete disappearance only occurred on the death 

 and partial decomposition of the animal. The disappear- 

 ance of the style during this experiment Barrois regards 

 as due, not only to the solution of its substance in the 

 stomach which goes on, as under normal conditions, but 

 also to the profound bodily disturbance brought about by 



* On the Anatomy of Pterocera, with some notes on the crystalline 

 style. Proc. Malacologieal Soc, London. Vol. I., pt. 4. 1894. 



