I 36 FERNANDUS PAYNE. 





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FIG. 6. Sinca diadeina Fabr. /i and B, female groups, metaphase figures, 

 showing 30 chromosomes the six small ones are the differential chromosomes ; 

 C and D, male groups, showing 28 chromosomes the four small ones are 

 the differential chromosomes ; E and F, polar views of the first maturation 

 division, metaphase, 16 chromosomes the four small ones are the univalent 

 differential chromosomes ; G and H, polar views of the second division, meta- 

 phase only three differential chromosomes are shown, as the fourth lies below 

 the three ; / and /, side views of the second division, metaphase, showing ar- 

 rangement of the tetrad group ; K and L, two anaphases of the second division, 

 showing the manner in which the tetrad group separates, and the number of 

 chromosomes in each of the two classes of spermatozoa ; M gives the typical 

 appearance of the plasmosome and differential chromosomes during the greater 

 part of the growth period ; N, a prophase of the first division after the plasmo- 

 some has disappeared the four small condensed bodies are the differential 

 chromosomes. A-L are magnified 3,726 diameters; M and N 2,411 diameters. 



