Nature does not proceed by leaps.
A herbarium is better than any illustration; every botanist should make one.
In natural science the principles of truth ought to be confirmed by observation.
The plant kingdom covers the entire earth, offering our senses great pleasure and the delights of summer.
Blessed be the Lord for the beauty of summer and spring, for the air, the water, the verdure, and the song of birds.
No one has been a greater botanist or zoologist. No one has written more books, more correctly, more methodically, from personal experience. No one has more completely changed a whole science and started a new epoch.