G. L. Kite 



stance of about 20 mm., a 2 mm. apochromatic objective, compensat- 

 ing oculars, and a number of vital stains, are necessary additions. 



An open-end moist chamber 25x60x15 mm. has been found 

 satisfactory. The bottom is separated into three compartments by 

 very small glass rods and water is placed in the end compartments. 

 If water be put in the middle compartment it may decrease the 

 efficiency of the condenser. The chamber is held in a mechanical 

 stage and most of the dissections are made by quick movements of 

 the chamber and therefore of the cell being dissected, the needle 

 remaining fixed. 



The use of acetylene which can be burned in a glass micro-burner 

 has greatly simplified the making of extremely fine needles. An 

 acetylene flame that is so small that it is invisible in a well-lighted 

 room can be kept alive. 



The more important of. the vital stains used include methylene 

 blue, new methylene blue N (Cassella Color Co.), new methylene 

 blue GG (Cassella Color Co.), new methylene blue R (Cassella Color 

 Co.), janus green (Metz & Co.), pyronin (Griibler), vusuvin (Griibler), 

 toluidin blue (Griibler), neutral red (Griibler). 



The chief structural components of a cell can usually be quickly 

 brought out by using a large enough number of vital stains, thus 

 effecting a great economy of time, when the dissection of the unstained 

 cell is made. 



Barber's 16 isolation and intracellular injection methods, vari- 

 ously modified, are frequently employed to supplement and control 

 the data obtained by dissection. 



Nomenclature Employed. The current nomenclature of de- 

 scriptive physics, physical optics and colloidal chemistry will be 

 employed. Such physical properties as solidity, tenacity, elasticity, 

 hardness and viscosity have been determined for the cells, so far 

 studied. In general, the term viscosity will be used to designate the 

 degree of rigidity of protoplasmic structures, but such a structure as 

 a vitelline membrane may be comparatively soft and yet have what 

 must be considered as a high internal friction or viscosity. Elasticity 

 is determined by transfixing a selected piece of a cell and stretching 

 it and observing the power of resumption of the original form. Dis- 



16 BARBER: University of Kansas Science Bulletin, 1907, iv, p. 3;. Journal 

 of infectious diseases, 1911, viii, p. 248; ibid., 1911, ix, p. 117. 



