“Stones grow, plants grow, and live, animals grow live and feel.”

In natural science the principles of truth ought to be confirmed by observation.

A herbarium is better than any illustration; every botanist should make one.

A professor can never better distinguish himself in his work than by encouraging a clever pupil, for the true discovers are among them, as comets amongst the stars.

If you do not know the names of things, the knowledge of them is lost, too.

Natural bodies are divided into three kingdomes of nature: viz. the mineral, vegetable, and animal kingdoms. Minerals grow, Plants grow and live, Animals grow, live, and have feeling.

It is not God, but people themselves who shorten their lives by not keeping physically fit.

A practical botanist will distinguish at the first glance the plant of the different quarters of the globe and yet will be at a loss to tell by what marks he detects them.

The species and the genus are always the work of nature [i.e. specially created]; the variety mostly that of circumstance; the class and the order are the work of nature and art.

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.

It is the genus that gives the characters, and not the characters that make the genus.

If a tree dies, plant another in its place.

When all the thoughts are concerning one thing and the person loses interest in other things, the melancholy begins.

Nature does not proceed by leaps.

This drink has a magical power. It strengthens the weak, and revives those who have fainted. Those tired after work and physical activity can return their life forces by this drink much sooner than by nourishment. It works as a diuretic, an appetizer, an antitoxin.

The greatest achievement was at first and for a time a dream. The oak sleeps in the acorn; the bird waits in the egg, and in the highest vision of the soul a waking angel stirs. Dreams are the seedlings of realities.

Man is a credulous animal, and must believe something; in the absence of good grounds for belief, he will be satisfied with bad ones.

I love dogs. I grew up with dogs in my family from the time that I was a little boy; we always had German Shepherds and Labradors. I get on very well with dogs, they trust me.

Struggle is the father of all things. It is not by the principles of humanity that man lives or is able to preserve himself above the animal world, but solely by means of the most brutal struggle.

Pet a cat when you encounter one on the street.

Vultures are the most righteous of birds: they do not attack even the smallest living creature.

Anyone who believes what a cat tells him deserves all he gets.

I am writing these poems From inside a lion.