132 Transactions of the Society. 



observers using chrome- or platinum-osmium fixatives, followed 

 by iron-alum haematoxylin, Benda's crystal violet, or Altmann's 

 acid fuchsin ; or by tlie useful methods of Cajal or Golgi, which 

 consist of silver-nitrate impregnation following formalin fixation. 

 Intra vitam methods, such as Janus green, neutral red, or Dahlia- 

 violet are also used extensively. The mitochondria are extremely 

 fuchsinophile, and after chrome-osmium fixation stain in an intense 

 manner in iron-alum haematoxylin. The Golgi apparatus of 

 somatic cells and of ovarian cells rarely stains by these methods 

 (Altmann or Haidenhain), although the Golgi apparatus of the 

 male germ cells nearly always stains in fuchsin or hematoxylin 

 after chrome-osmium fixation. 



To demonstrate the Golgi apparatus of somatic cells, or of 

 oogonia or oocytes, there are several methods ; the silver-impregna- 

 tion methods of Cajal or Golgi are useful, especially the former, 

 and in the hands of an experienced technician are fairly reliable ; 

 then there are the methods of Kopsch and Sjovall, which have as 

 their basis osmium tetroxide. Modern improvements on the 

 Kopsch method are those of Mann-Kopsch {IS), and Mann-Kopsch- 

 Altmann {11). 



On PI. II we endeavour to give true pictures of the ap- 

 pearance of various cells, after treatment of a tissue or organ, by 

 means of one of the above-mentioned special methods. In figs. 1, 

 2, and 9 we have cells impregnated by a formol-silver method ; in 

 figs. 4 and 5 the material has been stained byKopsch's method, 

 and in figs. 8 and 10 by iron-haematoxylin and acid fuchsin respec- 

 tively. 



To a greater or less extent most of these modern methods can 

 be controlled in such a way as to stain any given category of cell 

 body in a perfectly specific manner, though, as will presently be 

 noted, puzzling exceptions may be met with. It can be said, how- 

 ever, that a cytologist can generally distinguish between or stain 

 specifically — yolk, fat, glycogen, chromatin, mitochondria, and 

 Golgi apparatus. 



The problem, nevertheless, becomes very complicated when it 

 is found that one sort of cell granule or element may metamorphose 

 into, and become chemically altered to resemble another. 



Nomenclature and Definitions. 



!"? Archoplasm, Archoplasmic Splicrf. — A concentrated region of the 

 cell cytoplasm generally associated with the centrosome, and at 

 certain stages w^th the Golgi apparatus elements. The archoplasm 

 seems to have some relation to the amphiaster, but this has not 

 been conclusively established. The sphere or archoplasm is also 

 known as the idiozome (IMeves) {-^9), or, as it is sometimes wrongly 

 spelt, "idiosome.", 



