The jurors, or syndics, as they were more usually called, and whose number varied according to the importance of numerical force of the corporation, were generally elected by the majority of votes of their fellow-workmen, though sometimes the choice of these was entirely in the hands of the great officers of state. It was not unfrequent to find women amongst the dignitaries of the arts and crafts; and the professional tribunals, which decided every question relative to the community and its members, were often held by an equal number of masters and associate craftsmen. The jealous, exclusive, and inflexible spirit of caste, which in the Middle Ages is to be seen almost everywhere, formed one of the principal features of industrial associations. The admission of new members was surrounded with conditions calculated to restrict the number of associates and to discourage candidates. The sons of masters alone enjoyed hereditary privileges, in consequence of which they were always allowed to be admitted without being subjected to the tyrannical yoke of the association. [Illustration: Martyrdom of SS. Crispin and Crépinien. From a window in the Hôpital des Quinze-Vingts (Fifteenth Century).] Generally the members of a corporation were divided into three distinct classes--the masters, the paid assistants or companions, and the apprentices. Apprenticeship, from which the sons of masters were often exempted, began between the ages of twelve and seventeen years, and lasted from two to five years. In most of the trades the master could only receive one apprentice in his house besides his own son. Tanners, dyers, and goldsmiths were allowed one of their relatives in addition, or a second apprentice if they had no relation willing to learn their trade; and although some commoner trades, such as butchers and bakers, were allowed an unlimited number of apprentices, the custom of restriction had become a sort of general law, with the object of limiting the number of masters and workmen to the requirements of the public. The position of paid assistant or companion was required to be held in many trades for a certain length of time before promotion to mastership could be obtained. [Illustration: Fig. 243.--Bootmaker's Apprentice working at a Trial-piece.--From a Window of the Thirteenth Century, published by Messrs. Cahier and Martin]