No. 609] 



THE THEORY OF THE GENE 



531 



was made clear that the cytoplasm transmits these char- 

 acteristics only because they have been impressed on the 

 cytoplasm by the chromosomes at some earlier stage in 

 the history of the egg cell. They are strictly Mendelian 

 (Fig. 2). ' • 



It has also been suggested that the chromosomal, Men- 

 delian genes affect only trivial characters <iic]i as color, 

 while the more fundamc ndil charactci- arc cai-ricd in 

 the cytoplasm.' There aic ii. iraiity ik. un.iiii.N for as- 

 suming that some cliaractcrs arc more fmidamciital than 

 (.thcr-: ..r that mk-Ii 1in p.ithc.-at.'d t'lm.himcntal .-liai :!ct(M- 

 have a different ..mmI,^ of 1 „l,c, it ancc. The old fashioned 



char;icter> has long l)een recognized as entirely artificial | 

 and coti\ I'litional while the so-called promorphological 

 cliaiacieristics such as shape of egg, type of cleavage, 

 axial relations are as variable as are other characteristics, 

 and some of them, such as shape of egg, location of micro- 

 pyle, etc.. have been shown to fall under the ^^fendelian 

 fornnda. Take, for example, the following list of charac- 

 ters and try to decide whether they are fundamental 

 (generic) or only trivial; they are all Mendelian in some 

 cases at least; 



Sterilitv. several tvpes of which are recoi2:nized as ]\ren- 

 delian; 



