280 PHYSIOLOGICAL GENETICS 



assumption makes it possible to bring this cytoplasmic action 

 upon sex into line with other known cytoplasmic activities. 



G. Genes Controlling Cytoplasmic Properties 



We have already discussed on different occasions some of the 

 tacts that show that actually properties of the cytoplasm of 

 sex cells, especially egg cells, may be controlled by genes. It 

 may be useful to recount them again at the end of this chapter, 

 adding also plasmatic properties of the male gametophyte in 

 plants and chromosomal as well as nuclear behavior, which 

 itself is probably under control of the cytoplasm (see Boveri, 

 diminution in Ascaris). 



1. The spiral arrangement of spindle fibers in mollusk eggs, 

 controlling the dextral or sinistral coil in development (see 

 page 206). 



2. All other cases of so-called maternal heredity: Toyama and 

 Tanaka's work on pigments of the silkworm egg; the work of 

 Goldschmidt and Katsuki on abnormalities in the reduction 

 division and subsequent double fertilization in the same egg; 

 and the others quoted on page 206. 



3. Boveri's (1904) work on the control of chromatin diminution 

 in Ascaris by the cytoplasm may indicate that some of the genes 

 controlling details of chromosome behavior will actually turn out 

 to be genes controlling cytoplasmic behavior. The following 

 cases illustrate this possibility : Lesley and Frost's (1927) gene for 

 control of chromosome size in Matthiola; Emsweller and Jones's 

 (1931) gene for control of interstitial localization of chiasmata in 

 Allium fistulosum; Gowen's (1933) gene producing diploid or 

 subdiploid eggs in Drosophila; Beadle's (1930) gene for asynapsis, 

 (1931) gene for supernumerary cell divisions after meiosis, (1932) 

 genes for sticky chromosomes and pollen sterility. 



4. Many genes for pollen characters have been analyzed, e.g., 

 the aforementioned waxy gene (Brink), genes for pollen-tube 

 behavior (Brieger and Mangelsdorf, 1926), and many others. 



4. CONCLUSIONS 



Thus we conclude that the cytoplasm is mainly the substratum 

 for genie action, in which all those decisive processes take place 

 which constitute development and which are steered by the 

 genes. The specificity of the cytoplasm is therefore one of the 



