Studies on Chromosomes. 



377 





 * 



m 



n o 



Fio. i. 1 



Lygaeus turcicus. a, e, metaphase of first division in the first two figures several of the chromo- 

 somes are represented out of their natural positions at one side; b, c, normal melaphase-groups in polar 

 view, first division; d, abnormal form with nine chromosomes; /, the idiochromosomes and two others, 

 in early anaphase, first division; g, h, daughter-groups, late anaphase first division, from the same 

 spindle; /', j, equatorial plates of second division, at the metaphase, in polar view; k, prophase of second 

 division, showing all the chromosomes just before taking up their definitive positions; /, metaphase of 

 second division three of the chromosomes drawn out of position at one side; m, separation of the idio- 

 chromosomes, second division; n, o, daughter-groups, late anaphase of second division, from the same 

 spindle. 



'All of the figures were drawn as carefully as possible with the camera, a TS oil immersion, and 

 compensation ocular 12 (Zeiss), enlarged ^\ diameters with a drawing camera, carefully corrected 

 by renewed comparison with the objects and then reduced in the engraving to one-half. At such an 

 enlargement some error is unavoidable, but great care has been taken to represent the chromosomes 



