90 
Psyche 
[September 
Photomicrographs were taken on 35 mm. Adox KB- 14 film with 
the aid of a Micro Ibso attachment using a Zeiss 90X apochromatic 
oil immersion objective of NA 1.3 and a Leitz iox ocular. All 
films were developed with Neofin blau. 4 Prints were made on No. 5 
Kodabromide paper. Final magnification of all prints used in statisti- 
cal analysis was 3750X. 
Measurements of chromosome lengths were made from photomicro- 
graphs after the method of Boyes and Wilkes (1953), as modified 
by Robertson (1957), on A. fraterculus, A. mombinpraeoptans, and 
A. distincta whose karyotypes could not be distinguished by visual 
inspection. All measurements were carried out to the nearest 0.5 mm. 
and the percent of the total complement length of each chromosome 
pair calculated. A sine transformation was then made on the resulting 
percentages to reduce any correlation between the means and their 
corresponding variances (Snedecor, 1956). An analysis of variance 
was made on both the longest and the shortest chromosome pairs which 
were the only chromosomes that could be consistently identified with 
certainty. There was not sufficient evidence to reject the null hypothe- 
ses that in these three species the mean lengths of the long chromo- 
somes are the same or that the mean lengths of the short chromosomes 
are the same. (Short chromosome: F=2.28<F. 05( 2, 69)— 3 - J 3 - Long 
chromosome: F=2.5i<F 05(2 ;69) =3.I3.) The karyotypes of A. 
fraterculus, A. mombinpraeoptans, and A. distincta therefore could 
not be distinguished from one another on the basis of mensural 
observations. 
Description of Karyotypes 
The terminology used throughout the following descriptions and 
discussion of metaphase chromosomes is the same as that outlined 
by White (1957) except for the terms used to designate the position 
of the kinetochore or centromere. Major chromosome arms (MCA) 
were considered only when they were clearly visible in the metaphase 
plate as a point of flection or bend in the chromosome. This does 
not rule out the possibility of missing a short arm that would be visible 
only in anaphase configuration. Such chromosomes would be con- 
sidered acrokinetic. A metakinetic chromosome has two major arms 
with the kinetochore located near the center. Acrokinetic chromosomes 
have the kinetochore located near the end of the chromosome giving 
the appearance at metaphase of being one-armed. Dot chromosomes 
are treated as though acrokinetic, although in future investigations 
4 Neofin blau, Tetenal-Photowerk, Hamburg, Germany. 
