of the Salmon in Fresh Water. 



3. THE MINUTE STRUCTURE OF THE DIGESTIVE 

 TRACT OF THE SALMON, AND THE CHANGES 

 WHICH OCCUR IN IT IN FRESH WATER. 



BY G. LOYELL GULLAND, M.A., B.Sc., M.D., F.R.C.P.E. 



The digestive tract of the salmon has not hitherto been the subject 

 of any very detailed examination. Its general arrangement, of course, 

 conforms to that usual in the group of Teleosteans to which it belongs, 

 and it may here be divided into stomach, pyloric appendages, intestine, 

 pancreas, and liver. All of these were examined in the series of fish 

 under consideration. 



METHOD. 



The same method of preparation was used in all cases in order that 

 the results might not be affected by any deviation in this respect. As 

 early as possible small portions of the organs above mentioned were 

 removed from the fish and were placed immediately in a saturated 

 watery solution of corrosive sublimate. After 24 hours they were 

 rapidly washed in water and then passed through a series of alcohols 

 increasing in strength. They were embedded in paraffin, cut with the 

 rocking microtome, and fixed to the slide by my water method. One 

 set of sections was always stained with heematoxylin and eosin, whilst 

 other stains, especially the usual anilin dyes, were employed for com- 

 parison. The sections were all mounted in balsam. 



LITERATURE. 



The digestive tract of the salmon has never been examined micro- 

 scopically with special care in recent tunes, but the stomach of the nearly 

 allied trout has been described by Valatour (1), Cajetan (2), and 

 Oppel (3). 



The most important contribution to the subject hitherto has been 

 that by Miescher (4), who found that the stomach and gullet of the fish 

 taken at Basel, far up the Rhine, were contracted and folded, contrasting 



