90 



Edmund B. Wilson 



Described Cases 



' See Type Ha. 



Ill 



The female chromosome groups with one more chromosome than the male. 

 Male with an unpaired idiochromosome and an odd spermatogonia! number, half 

 the spermatozoa receiving the idiochromosome and half being without it. Female 

 with an equal pair of idiochromosomes like the unpaired one of the male. 



FERTILIZATIOM FORMULA 



Egg ? (including/) 4- spermatozoon ?? — i = zygotes — i (including/) c? 

 Egg ? (including/') + spermatozoon 5 (including/) = zygote n (including//) 9 



