218 
CHARLES L. PARMENTER 
exactly homologous to the components of ‘CV and ‘C 2 .’ The 
smaller member resembles those of ‘ C 2 ’ and may be homologous 
with them. It is important to note that the three last-mentioned 
authors find that each particular condition is constant for the 
individual in which it is found. 
Although tetrads with unequal homologues among the longer 
chromosomes have not been observed in the Orthoptera, they 
might possibly exist in other animals. The above observations, 
especially those of Wenrich, offer a possible explanation for the 
inequalities between homologues observed in Ambystoma as well 
as in Salamandra maculosa. Furthermore, the condition found 
in tetrad ‘C 2 ’ may offer a parallel explanation for the different 
relative lengths shown in some cases between corresponding 
pairs in complexes of different individuals (e.g., pr. 4 and pr. 
9). Of course much further data from both the somatic and 
germinal chromosomes is necessary before the above can amount 
to anything more than a suggestion. 
2. Certain inequalities might be explained as due to the 
presence of a multiple chromosome similar to that which has 
been described by McClung (’05, T7), in Orthoptera, by Boveri 
(’09), Edwards (TO, Tl), and Frolowa (T2), for Ascaris megalo- 
cephala, Boveri (Tl) and Edwards (Tl) for Ascaris felis, Stevens 
(Tl) in Anopheles, and by King (T2) for Necturus. In these cases 
the sex chromosome has been interpreted as being attached to one 
of the euchromosomes, and thus there is present in the male an 
unequal pair of chromosomes which may parallel the condition 
in pair 9 of figure 33 and pair 12 of figure 37. In certain Or¬ 
thoptera McClung (T7) finds that the accessory may be attached 
to different chromosomes in different individuals, which lends 
support to the possibility that this is the condition in Ambystoma. 
The presence of an X and a Y chromosome would also produce 
unequal homologues. 
If either of these explanations be valid, such an unequal pair 
should appear in all the diploid complexes of approximately 
one-half of a somewhat large number of individuals, and similar 
conditions should be found in the maturation period. Unfor¬ 
tunately, the difficulty of obtaining a sufficient number of suitable 
