V. V. Morozov, D. A. Gudkov and the first part of the $16$th Hilbert problem

We reveal some little-known facts from the history of the solution of the $16$th Hilbert problem. In particular, we consider the role of Professor V. V. Morozov (Kazan University) in the correction of errors in D. A. Gudkov's initial results about the topology of the plane real algebraic curves of degree $6$. The study is based on the preserved correspondence between D. A. Gudkov and V. V. Morozov.