338 CYTOLOGICAL METHODS. 



give mitochondria and yolk ; zymogen but not fat ; the latter will give 

 all these. Charapy-Kull and Bensley-Cowdry or Altmann methods are 

 next worth trying. Mann-Kopsch and Sjo'vall methods may present 

 difficulties, but again one might succeed at the first trial : if invertebrate 

 tissue, the Mann-Kopsch method will be best, if vertebrate, the Cajal 

 or Da Fano formalin-silver nitrate methods are most indicated for a 

 study of the Golgi apparatus. 



If your material is limited to a small amount, the Champy-Kull (or 

 Bensley-Cowdry) and the Mann-Kopsch methods are recommended : 

 successful preparations by both these methods will enable you to make 

 an almost complete study (sometimes of the chromosomes and) of the 

 cytoplasmic inclusions of every kind excepting glycogen.* Recom- 

 mended in the third place is a formalin-silver nitrate method Cajal or 

 Da Fano. See also GATENBY, Quart. Journ. Micr. Science, Ixiv, 1920, 

 p. 296, and E. V. COWPRY, Contrib. Embryology, Carneg. Inst., Washing- 

 ton, viii, p. 59. 



Addendum: SAGUCHI (Amer. Jour. Anat., Nov. 15th, 1920) finds 

 that the Golgi apparatus of acinus cells of the frog pancreas is brought 

 into evidence by Cajal's uranic silver nitrate method, and also by the 

 Weigl, Kopsch, and Sjovall methods, but that in islet cells, the former 

 method exhibits some other sort of apparatus. See -also SAGUCHI, ibid,, 

 vol. 26, 1920. 



* SHUN ICHI ONO (Anat., Anthrop. Ass. of China, 1920) finds that 

 osmicated mitochondrial fixatives preserve glycogen, which can be 

 stained in Best's carmine and iron hsematoxylin, the mitochondria 

 (grey black) and the glycogen (reddish) showing side by side. 



