Literary Notices. xv 



lateral line sytem, Ampullae of Lorenzini and vesicles of Savi of 

 Selachians. The structure of these interesting organs is investigated to 

 determine the mode of nerve termination and gain evidence as to their 

 function, — secretory or sensory. 



The Ampullae are discussed from the standpoint of their grouping, 

 gross anatomy, histology, innervation and physiology. The inner end 

 of each ampullary tube, the Ampulla proper, of which there are some 

 fourteen to fifteen hundred in Galeus, possesses lateral pockets 

 varying in number from 6 to 12 ; the nerve enters the base of the am- 

 pulla which is involuted forming a central column (the centrum) from 

 which radiate the partitions between the pockets. No special sensory 

 epithelium was found ; the ampullary tube itself is lined by a single 

 layer of rather flattened cells which also cover the upper surface of the 

 centrum cap. The walls of the pockets possess two layers of cells, a 

 surface layer and a deeper layer of short columnar cells. The inner- 

 vation of the ampulla can best be stated in the author's own words, — 

 " Five to seven medullated fibers coming from the (seventh pair of) 

 cranial nerves enter each ampulla from below and pass up the centrum. 

 Just beneath the centrum cap the sheath disappears. The axis cylin- 

 ders, continuing on their course, send out lateral branches, which after 

 division and ramification beneath the centrum cap run out along the 

 partitions to the outer walls of the compartments. Here minute fibrils 

 play over the bases of the deeper layer of cells, ending in slight en- 

 largements on their surfaces." (p 174.) 



The methylene blue method of intra-vitam staining was employed, 

 modified to suit the kind and nature of the tissue. 



Of the two possible functions, sensation or secretion, the former is 

 believed to be far the more plausible. In its support are arrayed the 

 rich nerve supply and the greater number and complexity in more ac- 

 tive Selacians than in those less active (Torpedo) — a correlation found 

 also in the lateral line system. 



The system is most puzzling, both as to its morphological signifi- 

 cance and its function— sensory though it be — and further work, espec- 

 ially bearing on the nerve supply in relation to that of the lateral line 

 system will be very welcome ; as also the results of experimental work 

 upon the function of the system, which the author has in progress. 



B. F. K. 



The Brain of the Sturgeon. 



J. B. Johnston, in the Zoological Bulletin, I, 5, describes the histol- 

 ogy of the olfactory tubers, the fore-brain and the habenular tracts in 

 Acipenser as made out by the Golgi method. In the olfactory tuber he 



