PLATE 9 



EXPLANATION OF FIGURES 



46 to 51 Ctenolabrus adspersus 9 X Stenotomus chrysops cf . 



4G The conjugating male and female pronuclei as they appeared in two neigh- 

 boring sections. 



47 Prophase of the first cleavage. 



48 ^letaphase of the first cleavage. 



49 A multipolar mitosis of the first cleavage, probably due to polyspermy. 

 The three types of chromosomes, rods, hooks, and V's, characteristic of Cteno- 

 labrus can be distinguished. 



50 and 51, A Characteristic anaphase figures of the first cleavage. No lag- 

 ging chromatin. 



51, B A section through six cells of an eight-celled egg from which figure 51, A 

 was drawn, showing numerous vacuoles in the cytoplasm. (Drawn with Zeiss 

 D objective and No. 2 ocular at table level.) 



280 



