I The chromosomes of Gryllotalpa borealis Burm.‘). 
By 
Fernandus Payne. 
With 2 figures in the text’. 
In the report of the meeting of the American Society of Zoologists 
(Science ’ll) Baumgartner States that in Gryllotalpa an odd chromo- 
some is present and that one of the tetrads divides unequally. At that 
time I was working on the same form, particularly the synaptic stages 
and the sex chromosomes. Lately, I have been able to follow the chromo- 
somes in the oogonial, spermatogonial and spermatocyte divisions and 
find an interesting chromosome combination. This combmation may be 
interpreted in one of three w'ays; first, as an unequal pah of idiochromo- 
somes and a supernumerary ; secondly, as a triad group simüar to that 
of Conorhinus, Fitchia (Payne ’09) or Thyanta (Wilson ’IO), with the 
exception that here the gronping occurs in the first dmsion instead of 
the second and that the two chromosomes which go to the female pro- 
ducing pole do not behave as a unit; thirdly, as an imequal pair of idio- 
chromosomes and an odd chromosome. 
For convenience of description, I shaU refer to this chromosome 
combination as a pair of idiochromosonies and an odd chromosome, 
although the evidence is not conclusive as to whether this is the correct 
Interpretation. 
The oogonial groups which were counted in only one individual 
Show twenty-four chromosomes (Fig. 1 A and B). WhUe some of these 
chromosomes are bent into more or less typical Fs, they are well sepai'ated 
(more than the figures show) and there is no doubt as to the correctness 
of this count. In Fig. 1 A, the chromosomes are not completely Con- 
densed; hence the difference in appearance between A and B. There 
1) Contribution from the Zoological laboratory of Indiana University No. 126. 
2) By mistake the figures are only one-fourth the size the author intended 
they should be. 
