464 E. ELEANOR CAROTHERS 



other like those represented in column 12, rows 7, 24, 26, and 28. 

 There seems, however, to be a tendency for the small ring of 

 such figures of 8 to rotate 180° so that it comes to lie within the 

 larger ring which at the same time rotates resulting in a form 

 such as that represented by chromsome 10, row 15. Obviously, 

 the ends of the smaller inner ring would separate early in the 

 ensuing division resulting in E forms like those represented in 

 column 12, rows 4 and 21. Those interested will find other 

 transition forms shown in the plates. 



c. An octad multiple. When the first two species of Cir- 

 cotettix studied showed twenty-one chromosomes in the sperma- 

 togonia and eleven in the first spermatocytes, it was at once sur- 

 mised that one of the four largest first spermatocyte chromosomes 

 is an octad. This assumption has been verified by the breaking 

 down of the octad into its component tetrads in a few cells of one 

 of the male offspring of mating number 5. Rows 13 and 14 repre- 

 sent two complexes from this individual. In the latter of these 

 two cells there are twelve chromosomes, eleven tetrads and the 

 accessory. There are three instead of the usual four large atelo- 

 mitics. The place of the missing atelomitic (column 11) is occu- 

 pied by a telomitic tetrad which would come about seventh in 

 the size series as arranged, while the other member of this poten- 

 tial octad combination appears as the lacking number 3. 



It was the conviction that one of the small pairs of chromo- 

 somes, either number 2 or number 3, had entered into a multiple 

 formation with one of the pairs of intermediate size rather than 

 that this chromatin had been lost' to the complex in the genus 

 Circotettix which caused me to leave ('17) a blank column in 

 the plate showing a serial arrangement of the chromosomes of 

 another species of this genus. 



Row 13 represents another complex from the same individual. 

 The octad here is only partially broken down at one end (column 

 11). A similar condition is shown in row 18, column 11. The 

 resemblance of this figure to the octad multiples of Hesperotettix 

 viridis is striking, as may be seen by comparison with the photo- 

 micrographs by McClung ('17), plate 8, figures Q to T. 



