The distinguishing feature of the man is his animation. He is full of good cheer, and acts as if he were expecting to discover something wonderful very soon.
To find the balance between play and work has been the aim of his life; and surely, he has pretty nearly discovered it.
Once when a caller asked him what he considered the greatest achievement of his life, he took out of his pocket a leather case containing a bronze medal, and proudly passed it around.
This medal was presented to him in the year Eighteen Hundred Fifty-nine, in token of a running high jump--the world's record at the time, or not, as the case may be. Haeckel is essentially an out-of-door man, as opposed to the philosopher who works in a stuffy room, and grows round-shouldered over his microscope. "I may entrust laboratory analyses to others, but there is one thing I will never let another do for me, and that is take my daily walk a-field," he once said.
While lecturing he sits at a table and simply talks in a very informal way; often purposely arousing a discussion, or awakening a sleepy student with a question. Yet on occasion he can speak to a multitude, and, like Huxley, rise to the occasion. Oratory, however, he considers rather dangerous, as the speaker is usually influenced by the opinions of the audience, and is apt to grow more emphatic than exact--to generate more heat than light.
The comparison of Haeckel with Huxley is not out of place. He has been called the Huxley of Germany, just as Huxley was called the Haeckel of England. In temperament, they were much alike; although Haeckel perhaps does not use quite so much aqua fortis in his ink. Yet I can well imagine that if he were at a convention where the Bishop of Oxford would level at him a few theological spitballs, he would answer, unerringly, with a sling and a few smooth pebbles from the brook. And possibly, knowing himself, this is why he keeps out of society, and avoids all public gatherings where pseudo-science is exploited.
There is a superstition that really great men are quite oblivious of their greatness, and that the pride of achievement is not among their assets. Nothing could be wider of the mark. When Ernst Haeckel was asked, "Who is your favorite author?" he very promptly answered, "Ernst Haeckel."