Complex sentence: Byomkesh gradually ages thorough out the series, and he has a son who is mentioned as Khoka (little boy) in the series, Saradindu doesn't want to continue the Byomkesh stories, that's why he stopped writing byomakesh stories from 1938 to 1951.
Split into simpler sentences: Byomkesh gradually ages thorough out the series, and he has a son who is mentioned as Khoka in the series. Sharadindu didn't want to continue the Byomkesh stories, that's why he stopped writing Byomkesh stories from 1938 to 1951.