Nature of Sexual Diversity 



131 



Figure 40. The exchange of the half nuclei in Paramecium caudatum, 

 after Maupas, 1889. The spindle-shaped bodies are the half nuclei. 

 A. The micronucleus of each member of the pair is dividing into two 

 halves, which are still connected by a band. The upper half in each 

 case is the "male" or "migratory" half nucleus. B. The two migratory 

 half nuclei are passing one another at the surface of separation of the 

 two individuals. (Each is still connected by a long band with the 

 other half (stationary) of the nucleus from which it came.) C. The 

 two migratory half nuclei are close together, but have now completely 

 lost their connection with the stationary halves. D. The migratory 

 halves have nearly separated, each passing into the body of the opposite 

 individual. E. The migratory and stationary half nuclei have come in 

 contact. F. The migratory and stationary half nuclei have almost 

 united. 



