"Owing to a long period of illness, Stoker was bedridden until he started school at the age of seven. Of this time, Stoker wrote, 'I was naturally thoughtful, and the leisure of long illness gave opportunity for many thoughts which were fruitful according to their kind in later years.' He was educated in a private school run by the Rev. William Woods."

What is "according to their kind"?
the people who has patience & consolation for himself

I take it to mean 'in different ways'.