778 report— 1884. 



apparently belong to sense-organs referable to the same category, and are dis- 

 tributed widely over the surface of the body. The histology of the portions of 

 skin containing these is not described. Again, in Esox } similarly scattered sense- 

 organs are met -with which, however, Ley dig considers to be identical in structure 

 with the beaker-shaped sense-organs or end-buds. 



In one of the commonest North American silurids, Amiums catus, the skin is 

 possessed of numerous small independent sense-organs, which unquestionably belong 

 to the type of ' Nervenhiigel ' (nerve-hillock), only they are neither so superficial 

 as the ' free ' nerve-hillocks of other Teleosts, nor included in a groove or canal like 

 the larger nerve-hillocks met with in the course of the lateral line, or in the canals 

 of the head. These structures are small flask-shaped sacs, occupying the whole 

 thickness of the epidermis, but not affecting the corium. The superficial epithelium 

 is continued into the mouth of the sac, which is lined by a cuticular border derived 

 from it, except in the fundus, where a few conical sensory hair-cells are found. 

 These are surrounded by imbricated supporting cells, 'Stiitzzellen,' which gradually 

 pass into the above-mentioned superficial epithelial cells. In the mode of their 

 distribution on the head, as well as in their histological structure, these sense- 

 organs recall the ' nerve-sacs ' of the ganoids, but, instead of being confined to the 

 head, they extend over the whole trunk on the dorsal and ventral, as well as on the 

 lateral aspects. "Whether they have any segmental grouping like the large nerve- 

 hillocks in the lateral canals must be a matter for future investigation. 



5. On the Function of the Air-bladder and, its rt lationship to the Auditory 

 Organ in Amiurus. By Professor R. Ram.say Wright, M.A., B.Sc. 



The anatomical features of the parts concerned have been already described in 

 a preliminary communication to the ' Zoologischer Anzeiger,' No. 162. The 

 functions of the air-bladder in the light of Moreau's researches were alluded to, 

 and it was suggested that the alterations of pressure incident to change of level in 

 water are communicated to the brain through the auditory nerve. Professor 

 "Wright supposes that the air-bladder is also sensitive to sound-waves, and that the 

 same channel of communication with the auditory apparatus serves for the trans- 

 mission of vibrations to the endolymph. In confirmation of the latter view 

 Professor Iladdon referred to the more specialised conditions in some tropical 

 siluroids, and to the stridulating apparatus described by him in some of these, 



6. On the Jessop Collection, to illustrate the Forestry of the United States, 

 in the New York Natural History Museum. By Albert S. Bick.moef. 



The great importance of the forest industries and lumber trade of the United 

 States led General "Walker, the Superintendent of the Tenth Census, to provide for 

 a corps of competent experts, under the direction of Professor Charles S. Sargent, 

 who have made new explorations of our forest lands, and gathered original data 

 regarding their present extent. The results of these elaborate researches have 

 been partially published from time to time in the form of bulletins, and the com- 

 pleted work will soon appear in two large quarto volumes of the census series. To 

 place this great fund of valuable information before the artisan and labouring 

 classes in an accessible form, a great collection of our forestry and its products was 

 needed, and this Mr. Morris K. Jessop offered to provide at his own expense. 

 After the field work planned by the census had been finished, Professor Sargent 

 directed his assistants to return to the forests, and to carefully select the individually 

 largest and soundest tree of each species. Professor Sargent is preparing a manual 

 which will be a guide to the collection, and which contains all the most important 

 information in the large census volume that will be useful to the visitors and to the 

 artisan classes. The museum is most fortunate in its location in Central Park, 

 where more native and domesticated species are flourishing than can be seen 

 together at any other place on the continent. This is the first effort yet made in 



