308 



T. H. MORGAN 



the two pairs of conjugated chromosomes have already united 

 before the spindle is formed. 



Von Baehr describes for Aphis sahceti a synapsis stage in the 

 spermatogenesis in which the chromosomes are contracted at one 



^B 



Diagram 4 Section of ovarj- of parthenogenetic female of second generation, 

 with large nutritive cells at one end and small egg cells at the other end on the 

 ovary. 



Diagram 5 Spermatogonial cells in prophase stages to left and one cell 

 in metaphase to right; all cells show five chromosomes. 



side of the cell. As no further details that identify this stage 

 were made out, one can not be certain that such figures repre- 

 sent the true conjugation stage. I have studied the spermato- 



