METHODS 



TABLE 7 



123 



COMPOSITION OF LAYERS IN CRUSHED ARBACIA EGGS IN PERCENT OF WHOLE EGG 



(McClendon 1909 a) 



Many other methods of preparing a homogenate or a suspension of 

 the contents of Arbacia eggs have been used. The important consider- 

 ation in obtaining a particulate system is to break up the eggs in a 

 medium devoid of calcium, since the yolk and pigment granules 

 disintegrate in its presence. The eggs may be ruptured by forcing 

 through a hypodermic needle from a syringe (Keltch, Strittmatter, 

 Walters, and Clowes, 1950), by grinding with sand in a mortar (Krahl, 

 Keltch, Neubeck, and Clowes, 1941), or by use of a Waring blender. 

 Subsequent centrifuging of the "brei" results in separation of the 

 various constituents, which can then be studied separately. Monroy 

 recommends for A. lixula, for jelly-free eggs: LiCl i M + NaHCOg 

 0.04 M + NagCOg o.oi M + Versene 0.0 1 M, in distilled water. Use 

 a Potter homogenizer (Personal communication July 1955). 



