TRANSACTIONS OF SECTION D. 635 



to illuminate a seriea of nets, is placed at the disposal of the biologist, and to fit 

 out a boat specially with an engine and dj'namo and a set of lamps would be a very 

 expensive matter. I thoug'ht at one time that storage batteries might serve the 

 biologist's purpose, but on making inquiries in Liverpool we found that for even a 

 day's work a considerable number of batteries woiUd have to Ije taken, and the 

 expense would be too great. The plan of sending a primary battery down in the 

 net, as in the case of the Hereditary Prince of Monaco's experiments, seems on the 

 whole — if it gives a bright enough light and works satisfactorily — to be the simplest 

 and most economical method, and the one which it would be best to adopt where 

 no vessel already provided with an electric installation is available. 



As to the practical application of this metliod to fishei'ie.s, although there can 

 be no doubt that the electricliglit acts powerfully in attracting many free-swimming 

 animals, and especially Crustacea, I think there is no good evidence that it attracts 

 marine fishes ; and, although more experiments are required before the matter can 

 be considered as settled, 1 am inclined at present to agree with the opinion which 

 has been expressed by some of the American investigators, that the method is of 

 more value to the scientific biologist than to the practical fisherman. 



On the Caudal liespiraiion of Periophthalmus. 

 Bij Professor A. C. Haddon, B.A., F.Z.S. 



I 



9. TJie Stomach of the Narwhal : the bearing of its Histology on Turner's 

 and Max Weber's Nomenclature of the Stomach of the Ziphioid and 

 Delphinoid Whales. By G. Sims Woodhead, M.D., and R. W". Gray. 



In a communication we gave before the Royal Society of Edinburgh last winter 

 we described, somewhat minutely, the histological structure of the stomach of the 

 narwhal {Mo7iodon monoceros). When this was written we had not read either 

 Professor Sir W. Turner's ' or Professor Max Weber's papers,- in both of which 

 we have most valuable observations and generalisations on the stomach of the 

 cetaceans. 



It is evident, on reference to the three papers, that although the main facts and 

 observations in all three are interpreted in much the same manner, there are slight 

 differences of opinion on some of the minor points. 



It is agreed that in all cetaceans, with the exception of the ziphioids, the 

 stomach is divided into what may be called an esophageal portion and a true 

 stomach, but there is some difference of opinion as to the methods of division and 

 nomenclature to be adopted in describing this true stomach. 



The first compartment or oesophageal diverticuhuu retains all the histological 

 elements and structure of the upper part of the oesophagus. The mucous mem- 

 brane is thick, the horny cells are arranged in regular lamellse, tlie deeper cells are 

 polygonal. The folds described by Turner we find to be true papillae, which 

 appear to project upwards as delicate filiform processes, ramifying somewhat 

 irregularly. This irregular ramification is sometimes so marked "that masses of 

 epithelium seem to be cut off", these then appearing to be very like gland acini, for 

 which, in allied species, they have by some observers, been mistaken. 



We assigned to this cavity a function which has been most aptly termed 

 'maceration ' by Turner in the paper above referred to. He speaks of this first 

 portion of the digestive apparatus as a ' macerating chamber.' 



In regard to the second compartment, or first true digestive cavity, there is 

 general agreement. It is spoken of as the cardiac or proximal division in all three 

 papers. For convenience of reference this is perhaps the best term. The glands 

 in the thick mucous membrane of this cavity are closely packed together and are 

 very numerous. They are simple, unbranched tubes, each continued downwards 



' 'Additional Observations on the Stomach in the Ziphioid and Delphinoid 

 Whales,' Joiirn. Aiiat. and Phys. vol. xxiii., pp. 46G ct svq. 

 ■ Marph. Jahrh. 1887-8, pp. 637 ct stq. 



