36 . Prof. E. W. Reid. The Process of [June 8, 



Such grand eruptions may well be expected to take place as stars 

 cool, and if in two or more dull and comparatively cool stars such a 

 state of things were imminent, then the tidal action due to their 

 near approach might be amply adequate to determine, as by a trigger 

 action, such eruptions. 



Under such conditions, fluctuations of brightness and subsequent 

 partial renewals of the eruptive disturbances might well take 

 place. 



. 



III. " The Process of Secretion in the Skin of the Common "Eel." 

 By E. WAYMOUTH REED, Professor of Physiology in Uni- 

 versity College, Dundee. Communicated by Professor 

 M. FOSTER, Sec. R.S. Received April 18, 1893. 



(Abstract.) 



Ley dig, more than forty years ago, demonstrated the possibility of 

 a secretory process in the skins of Fish by the discovery in the 

 epidermis of some twelve genera, of specialised cells to which the name 

 of "schleimzellen " was given. Since then Kolliker, Max Schultze, F. E. 

 Schulze, Foettinger, List, Leydig himself, and others have extended 

 our knowledge of the anatomical secreting elements of the epidermis, 

 and shown that in many instances it is extremely probable that 

 several varieties of such structures exist. Of the several forms of 

 glandular elements, the goblet cell is the most widely spread, and its 

 epidermic origin and development has been most carefully investi- 

 gated by F. E. Schulze and List. Considerable difference of opinion 

 has, however, arisen regarding the function of another form of special- 

 ised epidermic cell, viz., the club cell ("kolben" of Max Schultze), 

 which was originally described by Kolliker for Myxine and Petro- 

 myzon, though F. E. Schulze found that such cells also occurred in 

 Tinea, Leuciscus, Cobitis, JEsox, Silurus, and Anguilla, and Fritsch in 

 Malapterurus. Kolliker himself, in Myxine^ recognised the relation- 

 ship of these cells to the thread cells of the mucous sacs, first clearly 

 described by Johannes Miiller. Max Schultze, however, deemed them 

 to be of the nature of nervous end organs, possibly contractile, on 

 account of certain appearances in polarised light recalling those of 

 striated muscle fibre. H. Miiller, F. E. Schulze, Foettinger, Leydig, 

 and Fritsch, finding that these club cells are not constantly found in 

 contact with the corium, as Max Schultze thought, have all inclined 

 towards considering a secretory function probable for these struc- 

 tures, but have given no very definite information as to its details. 

 Quite recently PogojefP has again upheld Max Schultze's nerve end 

 organ theory in the case of Petromyzon. 



