to take with him were soon exhausted, and he was reduced to poverty, having, it is said, to wear other students' cast-off shoes, or mend his own with paper, when Olaf Celsius, Professor of Theology, observed his attention to botany, looked at his collections, and concluded that he would make a good assistant on the "Hierobotanicon," a treatise on the plants of the Bible, which he was preparing. He took Linnæus to board, gave him the free use of his library, found him some private pupils, and recommended him to Olaf Rudbeck, Professor of Botany. Linnæus had in the mean time had his attention directed to the sexuality of plants, by reading a letter from Burckhart to Leibnitz, a review of an address by Vaillant, and a work by Wallin, all bearing on the subject. He himself wrote a treatise on the sexes of plants, and it was this that Celsius made the occasion for the introduction. Rudbeck's advanced age did not permit him to attend personally to all his lectures, and he made Linnæus his deputy. The hand of the struggling student, who now at last, in his twenty-fourth year, saw his career taking an upward direction, was soon visible also in the remodeling and restocking of the academic gardens—he having become director in a place where his application to be employed as a subordinate had been refused a year before.
His equivocal position at the university having become unpleasant by reason of the jealousy it excited among the professors, Linnæus accepted a proposition from the Academy of Sciences of Upsala to make a scientific exploration of Lapland. He accomplished this task in the summer of 1732, depending mostly on his own resources, and, in the face of great difficulties and with no little danger, accomplishing a journey of forty-six hundred English statute miles, and brought home from it valuable fruit in knowledge and specimens. In 1734, after having been defeated by the hostility of one of the professors in an attempt to resume his lectures at Upsala, he performed, attended by seven pupils, a similar exploration of Dalecarlia. While on this journey, he lectured at Fahlun, to large audiences, and determined, at the suggestion of Chaplain (afterward Bishop) Browalius, to attend a foreign university for the degree of M. D. This would give him a position in society and science.
Arriving at Hamburg, he exposed the spurious character of a seven-headed hydra in a museum there which was composed of weasels' heads artfully sewn together, and so offended the proprietor of the establishment that he was obliged to leave the city at once. At Hardewijck he passed his examination, defended a thesis on the cause of intermittent fevers, and received his degree from the university. At Leyden he called upon Gronovius, who, upon being shown the "Systema Naturæ," was so delighted with it that he undertook to publish it at his own expense. The great