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



maceration in Ranvier's "third part" alcohol and teasing, and by 

 sections cut by the paraffin method. 



The club cells arise from the cells of the palisade layer by amitotic 

 division. Around the nucleus of the young cell a granular modifica- 

 tion of the protoplasm occurs, which is the forerunner of the forma- 

 tion of a vesicle which always bears a distinct relation to the nucleus 

 in its origin. The contents of the vesicle, at first homogeneous, 

 become granular, and a lattice work of the surrounding protoplasm 

 forms a distinct wall. In staining reaction the contents of this 

 vesicle differ markedly from those of the goblet cells described below. 

 They refuse to give the red- violet reaction with thionin, considered 

 by Hoyer as characteristic of mucin, stain well with soluble blue, 

 alone of all the dyes used, except that in sublimate specimens they 

 take the methyl green of the Biondi stain in contradistinction to the 

 body of the club cell which takes the acid fuchsin. 



At a later stage, by a vacuolation of the material of the club cell 

 round about the vesicle, it is set free, either as a cell with latticed 

 wall resembling the " Leydig's cells, " described by Leydig, Langer- 

 hans, Flemming, and Pfitzner in the epidermis of larval Proteus and 

 Salamander, by List in larval Triton, and Carriere and Paulicki in 

 Siredon pisciformis, or as a granular mass with some of the club cell 

 body material still adherent. (Formation of the " escape cell " or 

 " escape mass.") 



The remainder of the club cell forms a spirally coiled mass (" fibre 

 mass ") staining brilliant yellow with picrocarmine. 



Both " escape cell or mass " and " fibre mass " finally reach the 

 surface of the epidermis and are extruded, the granules and nuclei of 

 the former giving rise to the granules and nuclei of the slime, and 

 the latter becoming further broken up to supply the fibres. 



In the elimination of the elements derived from the club cells the 

 surface epidermis is lifted, and the spiral formation of the fibre 

 masses appears to aid in this act. 



The goblet cells are of the " footed " variety, and arise direct from 

 the palisade cells. They are pushed to the surface by the supply of 

 ordinary epidermic cells originating below. The young cells, with 

 closed theca in the lower layers, contain distinct granules in osmic 

 vapour or Flemming's fluid material, giving the red-violet reaction 

 with thionin and staining well with most basic dyes. There is no 

 evidence of List's " filar and inter-filar mass," except in those cells 

 which have nearly reached the surface, and whose contents are prob- 

 ably altered by imbibition. A process of regeneration of goblet cells 

 near the surface appears to occur, for after the discharge of the first 

 load of mucigen the protoplasmic foot remaining in the epidermis 

 grows, and develops the red-violet thionin reaction never present in 

 the fully developed goblet, except in the contents of the theca. 



