And profitable, too, though he was sometimes difficult to understand because now and then he used scientific technicalities which were above the reach of some of us.

They were pretty sure to be above my reach, but as he was quite willing to explain them I always made it a point to get him to do it.

I had a fair knowledge of his subject--layman's knowledge--to begin with, but it was his teachings which crystalized it into scientific form and clarity--in a word, gave it value.
His special interest was the fauna of Australasia, and his knowledge of the matter was as exhaustive as it was accurate.

I already knew a good deal about the rabbits in Australasia and their marvelous fecundity, but in my talks with him I found that my estimate of the great hindrance and obstruction inflicted by the rabbit pest upon traffic and travel was far short of the facts.

He told me that the first pair of rabbits imported into Australasia bred so wonderfully that within six months rabbits were so thick in the land that people had to dig trenches through them to get from town to town.
He told me a great deal about worms, and the kangaroo, and other coleoptera, and said he knew the history and ways of all such pachydermata.