At Easter, 1867, Haeckel returned to Jena through Morocco, Madrid, and Paris. He spent a few of the pleasant spring weeks at the Strait of Gibraltar and in the South of Spain. In the fine bay of Algeciras (opposite to Gibraltar on the west) the current of the Strait brought swarms of interesting medusæ, siphonophores, and other “plancton-animals” into his net. In his solitary walks through the mountain forests of Andalusia, in the incomparable Moorish palaces and the cathedrals of Seville and Cordova, Granada and the Alhambra, he gazed on that wealth of Spain in treasures of Nature and Art which had excited his boyish imagination in the vivid pictures of Washington Irving.
With his return home a crisis occurred in his career, from our biographical point of view, such as we find at one point or other in the lives of all great men. Up to the present the course of his life has advanced steadily onward, so that the simple chronological order afforded the most natural thread for our narrative. With this crisis his activity broadens out more. His ideas, almost all of which are presented in the General Morphology, form a great and continuous stem, which throws out a large or a small flower on one side or other, according to the stimulus received. His life crystallises about Jena; however many journeys he makes, he always feels that he will return to his centre at Jena. Nothing in his later career ever shook him from this ideal and personal base.
In the summer after his return to Jena, 1867, he married Agnes Huschke, daughter of the distinguished Jena anatomist. He shares the happiness of this second marriage down to the present day. Of their three children, the son is now a gifted artist at Munich; the elder daughter is the wife of Professor Hans Meyer, proprietor of the Leipsic Bibliographical Institute, who is particularly known in science by his ascent of the Kilimandschars; the younger daughter is still at home with her parents.
He never leaves the University of Jena—and it never abandons him. It is a kind of spiritual marriage. In 1865, when the sky was still free from clouds, he was invited to take a position at Würtzburg, his old school-place. He declined the invitation, and was then appointed ordinary professor at Jena. Then the evil days came. The conclusions of his Morphology were popularised by himself, and went out far and wide amongst the masses. People opened their eyes to find that this audacious scientist was making “war upon God” out of his zoology. At length the difficult question arises whether a mind of that type can be retained in the honourable position of official professor. The Philistines are in arms. The quiet, stubborn group, that has vegetated unchanged, like a demoralised parasitic animal, from Abdern to Schilda, through thousands of years of the free development of the mind, boycots the professor and his family for a time. The Philistines appeal from their safe corner to the authorities to intervene. Once, towards the close of the sixties, the situation threatened to become really critical. The head of the governing body of the university at the time was Seebeck, a distinguished man who by no means shared Haeckel’s views, but had a just feeling of Haeckel’s honourableness and mental power. In the middle of the struggle Haeckel approaches him one day, and says that he is prepared to resign his position, a sacrifice to his ideas. Seebeck replied, “My dear Haeckel, you are still young, and you will come yet to have more mature views of life. After all, you will do less harm here than elsewhere, so you had better stop here.” At Jena they still tell a similar story that happened on another occasion. A stern theologian presented himself in person at the chateau of Karl Alexander, Grand Duke of Weimar, and begged him to put an end to this scandal of the professorship of Haeckel, the arch-heretic. The Grand Duke, educated in the Weimar tradition of Goethe, asked, “Do you think he really believes these things that he publishes?” “Most certainly he does,” was the prompt reply. “Very good,” said the Grand Duke, “then the man simply does the same as you do.”
Haeckel remained a professor at Jena; and when the current subsided a little, he was not insensible of their liberality. He remained faithful to Jena, though even Vienna, amongst other places, offered him a position (1871). Under his guidance “zoological” Jena flourished like a poor orphan that has suddenly been enriched. At one stroke the university was lifted to the position of an intellectual metropolis for the whole of the young scientific generation of the last quarter of the century. The best of the younger men that fill the biological positions in Germany to-day (and many others) were educated under Haeckel. Many of these pupils became opponents of his eventually, but they all went through his system. He had a further satisfaction. He not only attracted the young men to Jena, but he conjured up as if by magic the financial resources for improving the external advantages of the place for teaching and working. His style of “zoology,” which was at the same time “natural philosophy,” brought people to his assistance who would never have been won by a narrowly technical zoologist, no matter how learned he was. Twice men were induced “for his sake”—that is to say, induced by the magnetic force of his charming personality—to leave large legacies to be spent on the university under his direction; once it was the Countess Bose, another time Paul von Ritter of Basle. Ritter alone gave sufficient to found two professorships at Jena for the express purpose of teaching the science of phylogeny that Haeckel had created.
All through the period of his long stay at Jena that followed we trace a series of continual holiday journeys. In these journeys he used to collect the best material for his professional research, following the method he had learned from Müller at Heligoland, and had practised at Messina and Lanzarote. At the same time these travels were, like the earlier ones, the bath of eternal youth and health for “the other soul in his breast”; the artist, the lusty wanderer, I might almost say the inveterate Bohemian in him, was then allowed to have his spell of song and gaiety. In Jena he took deeper and deeper root as time went on. There was something in him in this respect of a Persephone impulse, an alternation of winter and summer in his life. When the days of hard and wearing work were past, he would have to rush away into the free air, down to the blue sea, to far and happy Nature. “Here I am a man—dare be a man.” The duty of the zoologist of Müller’s school to go down to the sea to work came to his rich temperament, which included so much more than mere “professional reasons,” with a splendid sense of Persephone-life: half his time in the cold North studying animal skeletons and dead bones by the burning lamp, the other half in the glare of the sun of reality, in living nature at its best. I will only quote summarily a few dates of these travels. In 1869 he spent the autumn vacation in Scandinavia. In 1871 he was in the island of Lesina in Dalmatia, where he, the arch-heretic, lived in a monastery with a jolly abbot. From beautiful Ragusa he made an interesting excursion to Cattaro and Montenegro. In 1873 he went to Egypt and Asia Minor, visiting Athens, Constantinople, Brussa, and the Black Sea. The culmination of this journey was a visit to the splendid coral banks of Tur, in the Red Sea. The Khedive, Ismail Pacha, put a Government steamer at his disposal for the journey. The excursion has been superbly described by Haeckel himself in the little volume, The Corals of Arabia (1876). The same volume contains the first specimens of his landscapes in water-colour. He spent the spring of 1875 in Corsica and Sardinia. On that occasion Oscar Hertwig discovered, in his presence, the process of fertilisation in the sea-urchin; his discoveries will long remain a turning-point in the history of our knowledge of sexual generation (one of the deepest mysteries in nature). In the autumn of 1876 he was at work on the coast of Great Britain, and reached as far as Ireland. In the spring of 1877 he was at Ithaca and Corfu; in the autumn we find him on the Riviera. In 1878 he went first to Fiume and Pola on the Adriatic, and afterwards on an Atlantic excursion to Brittany, Normandy, and Jersey. In the autumn of 1879 he was in Holland and Scotland.
In 1881 he made the second longest journey of his life. He secured permission to absent himself from the university for six months, and went to Ceylon. He left Jena on the 8th of October, and did not return until April 21, 1882. The traveller and æsthete in him revelled in this first plunge into the tropics. How he was taken to the enchanted land of India in the Lloyd steamer Helios, a pretty reminiscence of the “heliozoa” (sun-plants), a name he had himself invented; how he greeted his beloved medusæ in their beautiful tropical forms of the Indian Ocean; how he lived in the execrable but thoroughly tropical and interesting Whist-Bungalow at Colombo, where mysticism and an unholy joy in card-playing occupied him until philosophic zoology came to crown and redeem everything; how he set up his zoological laboratory far from the world at the Cingalese village of Belligemma (which he interpreted bella gemma, the “pretty jewel”), and fished with his Müller-net for radiolaria, medusæ, and siphonophoræ, for six whole weeks, to the intense bewilderment of the naked children of the palms; how he at last penetrated into the wildest virgin forests of Ceylon, where one heard the heavy tread of the elephant and the roar of the panther—all this he has described in his Visit to Ceylon, the freshest expression of his temperament, which belongs utterly to the free, artistic half of his life, when Persephone has her summer days in the land of flowers.
He himself regarded this journey, happy and favoured to the very last minute, as a crown and conclusion of his travels that could never be surpassed. But many a long hour was to be spent in travel after that, and he was to make one journey that left Ceylon far behind him in the Indian Ocean. In the spring of 1887 he made a pilgrimage to the “Holy Land,” Jerusalem and the Dead Sea, Damascus and Lebanon. On this journey he spent a delightful month on the island of Rhodos. In 1889 he had a pleasant time on the beautiful island of Elba. In 1890 he visited Algiers, where his innocent sketches and his anatomical knife brought suspicion on him; they arrested him and threatened to shoot him as a spy. He has described the incident in his genial way in his Algerian Reminiscences which is, unfortunately, lost in a back number of some magazine or other, like so many of the sketches of his travels. In 1897 he travelled over the whole of Russia, from Finland to the Caucasus, and visited Tiflis, Colchis, and the Crimea. In the autumn of 1892 he accompanied Sir John Murray, of the Challenger expedition, on a small deep-sea investigation on the coast of Scotland. In the spring of 1893 and 1897 he was at work once more in his beloved Messina, where he was now honoured as a world-famous guest. In the autumn of 1899 he climbed the Sabine and Corsican hills. As the second decade after his first journey to the tropics came to an end, he seemed to regard all he had done so far as a small payment on account. In his sixty-sixth year he felt the “home-sickness” for the tropics once more with such intensity that he quickly made up his mind to go as far as the equator. He left Jena on August 21, 1900, and (after a brief visit to the exhibition at Paris) took ship at Genoa, on September 4th, for Singapore. His beloved Italy had provided part of the cost of the journey. In the previous year the Royal Academy of Science at Turin had awarded him the Bressa prize (consisting of 10,000 lire) on account of his Systematic Phylogeny. Once more the tropics revived the great impression made on him in his earlier visit. This time he spent only a few hours in Ceylon, and sailed further south. He landed at Singapore on September 27th, and sixteen days afterwards went on to Java, and thus crossed the equator at last. He enjoyed to the full the charms of the landscape with its volcanoes and virgin forests, during his stay with Treub at Buitenzorg, at Tjibodas, and during his long journey across the greater part of the island. At Tjibodas he celebrated the close of the nineteenth century [German calculation] by painting a fine water-colour of the smoke-canopy over the summit of the volcano Gedeh, touched and gilded by the east rays of the sun on the last day of 1900. On January 23, 1901, he went from Batavia to Sumatra, crossed the Sunda Strait in sight of the famous volcanic ruins of Krakatoa, and spent six weeks in Padang on the south-west coast of Sumatra. This delay was largely involuntary, and due to an injury to his knee, caused by stumbling over a rail during a visit to an engineering establishment; but the time was by no means lost in the middle of such glories. On March 31st he landed in Europe (at Naples) once more, after a safe voyage. The notes he made during his journey yielded another charming work, Letters from the East Indies and Malaysia (1901). His spirit of enterprise is inexhaustible, and still continues.
Within this frame of his career we have now to study a growth of ideas and a continuance of research that tell of vigour, consistency, and success in every line. It unfolds logically like a great work of art.