@line = split(/(\.)/,$line);

##</code><code>##

If the PATTERN contains parentheses, additional list elements are created from each matching substring in the delimiter.

##</code><code>##

while(<DATA>) {
    $line=$_;
    chomp($line);
    @line = split(/(\.)/,$line);
}

print Dumper(@line);

__DATA__
The quick. Brown fox. Jumps over the. Lazy dog.

##</code><code>##

@line = (
          'The quick',
          '.',
          ' Brown fox',
          '.',
          ' Jumps over the',
          '.',
          ' Lazy dog',
          '.'
        );