196 CHARLES L. PARMENTER 



the criteria adopted are not entirely satisfied. There is a chance 

 of doubt, therefore, of the vahdity of the pairs as indicated. 



As mentioned above, it will be noted that the groups into 

 which the chromosomes of this cell are associated are repeated 

 in the other cells. The similarity of grouping is very marked, 

 especially in the formation of two large and distinctly separated 

 groups, one containing pairs 3 to 7 and the other pairs 9 to 14. 

 In pairs 3 to 7 of figure 34 the condition present in figure 33 is 

 duplicated, except that pair 3 is not so well separated from pair 

 4, due to the fact that both homologues of pair 4 are relatively 

 shorter in the former complex. Concerning the homologues of 

 pair 6 there is some doubt. I have interpreted the end of 

 chromosome 30 + (fig. 28) as bending back upon the main 

 portion of the chromosome, and have estimated the length of 

 this portion. 



Of the remaining six pairs (9 to 14) in both cells several are 

 quite clear, but on the whole the possibilities of error and the 

 differences in length between successive pairs is too small to 

 satisfy the second criterion fully. In figure 33, on account of 

 the practical absence of twisting in pair 12 and adjacent pairs, 

 the condition for determining pairs is very closely satisfied. 

 The chromosomes of pair 9 were considered homologues through 

 a process of ehmination. They differ 12.4 mm. in length, but 

 agree in form (fig. 27). This condition will be discussed later 

 (p. 217). 



In figure 34, pairs 9, 11, and 13, although not sufficiently 

 separated to constitute an unquestionable demonstration of pairs, 

 are fairly well separated and the homologues of each pair, after 

 allowance is made for errors due to twisting, are of nearly equal 

 length. One homologue of pair 10 (fig. 28) is imperfect. Pair 

 14 is well separated in the graph from pair 13. Approximate 

 corrections made for the kink in the shorter member and for 

 the slight foreshortening at that point make its length approxi- 

 mately the same as that of the longer member. The homologues 

 of all these pairs agree very well in form (fig. 28), in spite of the 

 fact that some may not yet have assumed their final shape. 



