CHAPTER XXV 7. 



337 



out ; those of the egg can generally only be demonstrated by 

 methods 1 and 2. The fat-methods of Daddi, Herxheimer 

 Martinotti, and Lorrain Smith should be tried as well, and reference 

 made to tables given below. If yolk granules contain olein or such 

 unsaturated fat they will stain in Os0 4 like fat, but by slow de- 

 colourisation as in paragraph 2 (with turpentine), their proteid 

 basis will be noted, and they will generally be demonstrated in 

 methods 1 and 4, while fat vacuoles disappear completely. 

 See also the special sections on " Fat," 768 to 772. 



712. Inclusions in Gametogenesis. 



713. Plan for Cytological Research. It is best to work at some animal 

 which is procurable in sufficient numbers, as frequently your first pre- 

 parations are disappointing. If a vertebrate, begin with Regaud, and 

 stain in iron alum haematoxylin ; if an invertebrate try Flemming 

 without acetic acid, and iron hsematoxylin ; the former method will 



M. 



