It is widely recognized that a key to the more complete exploitation of solid state nuclear track detectors lies in knowledge of the ways in which a particle is brought to rest, and how its energy is stored as lattice defects. One indirect way of looking at latent tracks — in an effort to bridge the micro/macro — has been small angle X-ray scattering, and the subsequent, multi-parameter model has spawned others for different solids. This work led to the so-called “gap model”, in which intermittent extended defects are separated by point defect rich regions. Latent intermittent fission fragment tracks were seen as long ago as 1962, using direct transmission electron microscopy (TEM). It is shown, in more detail, that the intermittency arises from periodic bursts of electronic energy loss along the particle trajectory, and that this makes it possible to measure the thickness of a crystal, using TEM, to an accuracy of one atomic (or molecular) layer. In other words anisotropy of the basic crystal lattice is responsible also for the latent track structure, as it is for the well-known angular variations in particle ranges evidenced in etched track polar plots, for which “channelling” and “quasi-channelling” are responsible. Simple probability theory, isotropic fragment emission, and the lattice structures of muscovite mica and molybdenite are used to predict the most probable extended defect length for at least an order of magnitude comparison with the X-ray work, since crystal orientations are not specified. Speculation is made on the consequences of this work for the etching of latent tracks.