Ontogeny, or the individual development of an organism, is a complex process, which is influenced by various factors. What can be the cause of ontogeny, what are its main stages?
The ancient Slavic word "sagittarius" denoted an archer, who was the main component of medieval troops. Later in Russia they began to call representatives of the first regular army that way. The Streltsy army replaced the pishchalnik militias. Boyar children commanded "orders"














