636 SUMMARY OF CURRENT RESEARCHES RELATING TO 



ing a single young Actinid ; as the zoarinm increases, and the cells 

 grow round the mouth of the cavity occupied by the latter, the canal 

 is constantly being elongated, as the sea anemone remains at its 

 orifice, and thus prevents it from being encroached upon by the 

 multiplying cells. Sometimes the sea anemone gives off a lateral 

 bud, and at this point the canal is seen to branch, and by degrees, by 

 the simultaneous growth of the Bryozoon and the sea anemone, such 

 a complex organism as the author has described is produced. 



MoUusca. 



Digestive Processes in Cephalopoda.*— E. Bourquelot finds that 

 the secretion of the salivary glands of Cephalopods has no action on 

 raw or on hydrated starch ; the hepatic secretion converts the latter 

 into sugar, and the pancreatic juice has a similar action ; in other 

 words, we may say that the ferment produced by the liver and pan- 

 creas is identical with the salivary ferment of higher animals. 



The author is of opinion that the action of the ferment ought to 

 be considered separately from that of hydration. If in any animal 

 raw starch becomes saccharified, we must suppose that it has been 

 previously hydrated under conditions which are, as yet, unknown 



to us. 



There is at present no evidence which would lead us to think that 

 the liver of Cephalopods forms glycogen ; the so-called liver is then, 

 from a physiological point of view, a pancreas, for it contains a peptic 

 and a diastatic ferment. The author concludes by merely adverting 

 to the difficulty of explaining the presence of this last ferment in 

 carnivorous animals. 



Suckers of Cephalopods.f — P. Girod describes the suckers of 

 Octopus vulgaris and Sepia officinalis, which are, at first, to be distin- 

 guished from one another by their sessile condition in the former, and 

 their pedunculated character in the latter ; in the Decaj^od there is, 

 further, a horny ring developed, but there is not, as in the Octoj)od, 

 any elastic cup or constriction, the cavity of the sucker forming a 

 single chamber. 



In the Octopod the suckers act thus: the animal contracts the 

 extrinsic infundibular muscles, the sphincter of the orifice, and the 

 inferior muscular envelope, and the form of the sucker becomes per- 

 fectly plane. Then the infundibulum or upper portion of the sucker 

 becomes conical, the acetabular chamber enlarges, and its orifice dilates 

 slightly ; a vacuum is thus formed, and any pulling on the sucker 

 only tends to separate the orifice from the base of the sucker, and so 

 to increase the vacuum. In the Decapod there is a piston-like 

 arrangement which becomes withdrawn by the action of lateral 

 muscles, while the horny ring becomes more firmly attached. As the 

 author justly points out, his results will be more completely displayed 

 when he gives an account of the minute structure of the parts which 

 he here mentions. 



* Arch. Zool. Expe'r. et Gen., x. (1882) pp. 385-421. 

 t Comptes Rendus, xcvii. (1883) pp. 195-7. 



