18 



J. BRONTK ftATENBY 



(acotic) fixatives, which oithor wash away the fatty yolk or 

 the mitochondria, or hoth, and leave the nucleolar doutoplasrn. 

 Then there are the formalin silver-nitrate methods which 

 stain the Golgi elcanents. The table below shows the follow- 



ing 



Method 1 constitutes a difference between mitochondria 

 and nucleolus and its derivatives. 



Method 3 constitutes a difference between nucleolus and 

 its derivatives and true fatty yolk (from Golgi elements). 



Method 4 constitutes a difference between nucleolus and 

 Golgi apparatus. 



Method 5 constitutes a difference between Ciolgi apparatus 

 and mitochondria, as also do Methods 1, 2, and 3. 



Table. 



8. Centrifuge Experiment on the Ovarian Oocyte. 



Live specimens of Saccocirrus were placed in a tul)e and 

 centrifuged for twenty minutes at 3,000 to 5,000 revolutions 

 a minute. They were afterwards throw^n into capsules of 

 fixatives of various types. The centrifuged egg shows three 

 layers, viz. an upper cap, a clear subcentral zone, and 



