  The exposition of the theory of structure species in Bourbaki's tractate
takes only a few pages but still is quite difficult. However, in the exercises,
Bourbaki outlines another approach that is based on the notion of structure
type rather than the notion of echelon construction scheme. Herewith, relying
on the permissible limits common sense, one can proceed without complicating
consideration the concept of the balanced string of signs, and then get quite
affordable and at the same time sufficiently rigorous exposition. That's what
we are doing by following the path proposed in this doctoral thesis. To make
the presentation as accessible as possible, we have included in it a large
number of examples. The work ends with the definition of kind structure. The
author hopes to continue work, including in her consideration of the three main
species of the general structures combined structures and structures with
morphisms.
