push(@abst_listing,$abstracts[1]);

##</code><code>##

# at the top of your script:
use Data::Dumper;

...
my $a; 
my $b; 
my $c;
# *** find out what the contents of your arrays is
print Dumper(\@abst_listing,\@cont_names,\@bact_names);
for ($a=0; $a<= scalar(@abst_listing); $a++){
    for ($c=0; $c<= scalar(@cont_names); $c++){