40 Process of Secretion in the Skin of the Eel. [June 8, 



such violent action that the whole epidermis is loosened. An almost 

 " volcanic " eruption of " fibre masses " from the club cells occurs, 

 and at the same time many new goblet cells appear in the lower 

 layers. This result, so far as concerns the club cells, is of reflex 

 origin, for chloroform vapour applied to the exsected skin does not 

 produce the effect. There is, then, physiological evidence of a con- 

 nexion between the club cells and the central nervous system, 

 though I have been unable to obtain convincing proof of actual nerve 

 fibrils by the use of gold. The surface of the epidermis may be com- 

 pletely thrown off by the rapid production and uncoiling of the 

 " fibre masses " of the club cells. At the same time a rapid passage 

 of fibroblasts into the epidermis takes place, probably with a view to 

 affording support to the epidermic elements during the subsequent 

 regenerative processes that must occur. This inroad of fibroblasts 

 may be so great, and the secretory activity so violent, that, under 

 such circumstances, whole masses may be extruded still in the 

 elementary lymphocytic form. 



The action of faradisation is less violent, but, not being followed 

 by any narcotic action upon the elements, may be employed to obtain 

 a picture of the result of prolonged stimulation. In such experi- 

 ments the epidermis is found bereft of superficial cells, and its 

 surface covered -by a mass of extruded club cells and fibre masses, 

 if the stimulation has been carried out in air. Dividing nuclei in 

 both the palisade cells and ordinary epidermic cells are far more 

 frequent than normal, and, as before, the number of fibroblasts is 

 excessive. 



By poisoning Eels with atropine a condition of the epidermis is 

 found in which the club cells go through their metamorphosis while 

 still in contact with the corium, the surface epidermis is intact, and 

 the whole structure becomes thicker from the formation of epidermic 

 cells without concomitant removal. 



In conclusion, it should be noted that, by stimulating specimens of 

 Petromyzon fluviatilis with chloroform vapour, evidence has also been 

 gained of a similar production of fibres from the bodies of the club 

 cells. The conclusions stated at the end of the communication of 

 which the above is a short abstract are as follows : 



1. The secreting elements of the epidermis of the Common Eel 

 consist of goblet cells and club cells, both direct descendants of the 

 cells of the palisade layer. The former supply a mucin, the latter 

 threads and a material appearing as fine granules in the slime. 



2. The goblet cells contain mucin granules, and, after reaching 

 the surface and discharging their load, are capable of undergoing 

 regeneration by growth of the protoplasmic foot and re-formation of 

 mucin. 



3. The threads of the slime resemble those of Myxine glutinosa, 



