These spectacular discoveries in biochemistry ran far ahead of the
genetic study of the pneumococcus transformation, which relied on the
capsule as a sole genetic marker. Until this study was broadened about
1951 with experiments on drug resistance and other markers 18, 91, a
variety of opinions were forwarded (mostly on a purely speculative level)
on the biological interpretation of CM&h's finding. They included the
following versions of the transforming substance :
1. It was a specific'mutagen with a special ability to direct a par-
ticular gene to mutate in a definite direction.
2.  It was a polysaccharide autocatalyst (perhaps as a complex with
DNA) that primed an enzymatic reaction for polysaccharide synthesis.
3.  It was a bacterial virus, which on infecting the bacteria provoked
capsular synthesis as a host reaction.
4.  It was an autonomous cytoplasmic gene or a morphogenetic in-
ducer.
5. It might be acting at a distance without penetrating the bac-
terium.
6. IL WS 5 frqymnt of the genetic make-up of the bacterium, the
(JIlIy ON t0 hVC bCCIl tXStcd to that time.
7. It was an fh-m3~t sui ~eneris for which 110 g;encral co~~ception
should be aclduccd.