Fig. 10.3-12. Magnification of oleander crypt. This crypt appears to lack an opening to the atmosphere outside the leaf. Do you think that is correct?

            This section cuts through the edge of the crypt, just missing the opening. We cannot be absolutely certain of that from this one single section, we know it because oleander is a species that has been studied carefully. If this were a species being examined for the first time, or if it were a newly created mutant in a genetic engineering experiment, we would need to examine serial sections to ascertain whether there is indeed an opening or not.