Goethe probably owned neither hamsters nor guinea pigs. Perhaps that is why he did not know what pet owners quickly learn: rodents must gnaw, as the prominent incisors of this species would otherwise grow uncontrollably and the animal would starve. Thus, the poet found the almost compulsively passionate, unintentionally destructive nibbling of these rodents to be a source of unease. This is also contributed to by the unstable, fluctuating appearance of this diverse species, which is left to a certain randomness of form to the point of formlessness. Such formulations, which are less known compared to Goethe's morphological core statements, provide a reason for a re-reading of his notebooks on morphology (1817-1824) as a keen and surprisingly untroubled, yet equally sustainable theory of temporally conditioned life forms.