Inspired by the example of his brother, he conceived the plan of collecting, in a single work, all that had been previously written upon plants, and, especially, of drawing up a concordance of all the names given by different authors to the same species. His extensive early travels served as a good preparation for this task, since he had not only observed and collected widely, but had established relations with the best botanists in Europe. He formed a herbarium of about 4000 plants, including specimens from correspondents in many countries, even Egypt and the East Indies. Besides study bearing directly on his great project, he accomplished a considerable amount of critical and editorial work, which also had its value in relation to his main plan. He produced new editions of Mattioli’s Commentaries, and of the herbal of Tabernæmontanus, and published a criticism of d’Aléchamps’ ‘Historia plantarum.’ There is a marked parallelism between the careers of the Bauhin brothers, for Gaspard’s great work underwent much the same vicissitudes as that of Jean. The main part of Gaspard’s chief work never saw the light at all, although his son brought out one instalment of it, many years after his father’s death. Gaspard was however more fortunate than Jean, in that he lived to see the publication of three important preliminary volumes, as the result of his researches, and it is on these that his reputation rests. [Illustration: _Plate XI_ GASPARD BAUHIN (1560-1624). [Theatrum Anatomicum, 1605.]] [Illustration: Text-fig. 49. “Solanum tuberosum esculentum” = Potato [Bauhin, Prodromos, 1620].] The ‘Prodromos theatri botanici’ of 1620 consisted of descriptions of 600 species, which the author regarded as new, although several had, as a matter of fact, been already described by de l’Écluse. Figures of about 140 species are given, two of which are here reproduced (Text-figs. 49 and 62). One of these, the Potato (Text-fig. 49), still retains the name of _Solanum tuberosum_ which Bauhin gave to it. He had previously published a description of this plant in an earlier work, the ‘Phytopinax’ of 1596.