great number of genre works. Another popular source of meaning is visual puns using the great number of Dutch slang terms in the sexual area: the vagina could be represented by a lute (luit) or stocking (kous), and sex by a bird (vogelen), among many other options, and purely visual symbols such as shoes, spouts, and jugs and flagons on their side. The same painters often painted works in a very different spirit of housewives or other women at rest in the home or at work – they massively outnumber similar treatments of men. In fact, working-class men going about their jobs are notably absent from Dutch Golden Age art, with landscapes populated by travellers and idlers but rarely tillers of the soil. Despite the Dutch Republic being the most important nation in international trade in Europe, and the abundance of marine paintings, scenes of dock workers and other commercial activities are very rare. This group of subjects was a Dutch invention, reflecting the cultural preoccupations of the age, and was to be adopted by artists from other countries, especially France, in the two centuries following. The tradition developed from the realism and detailed background activity of Early Netherlandish painting, which Hieronymus Bosch and Pieter Bruegel the Elder were among the first to turn into their principal subjects, also making use of proverbs. The Haarlem painters Willem Pieterszoon Buytewech, Frans Hals and Esaias van de Velde were important painters early in the period. Buytewech painted "merry companies" of finely dressed young people, with moralistic significance lurking in the detail. Van de Velde was also important as a landscapist, whose scenes included unglamorous figures very different from those in his genre paintings, which were typically set at garden parties in country houses. Hals was principally a portraitist, but also painted genre figures of a portrait size early in his career. A stay in Haarlem by the Flemish master of peasant tavern scenes Adriaen Brouwer, from 1625 or 1626, gave Adriaen van Ostade his lifelong subject, though he often took a more sentimental approach. Before Brouwer, peasants had normally been depicted outdoors; he usually shows them in a plain and dim interior, though van Ostade's sometimes occupy ostentatiously decrepit farmhouses of enormous size. Van Ostade was as likely to paint a single figure as a group, as were the Utrecht Caravaggisti in their genre works, and the single figure, or small groups