In pragmatics, it is widely accepted that the overall meaning of an utterance performed as part of a verbal interchange is basically underdetermined by the meaning of the sentence uttered. What counts as having been said for most contemporary authors goes far beyond sentence meaning. Rather, it has to be considered as a complex utterance level combining semantic knowledge and context-driven, pragmatic information as an integrated whole. The focus of the present book lies on central questions about the nature, the function and the acquisition of pragmatic inferencing strategies. The question of the relation between the explicit and the implicit side of verbal communication and its mutual delimitation is addressed. What is the character of pragmatic inferences, wherever they may be situated in a descriptive model? Are they nonce inferences arising anew in each act of communication, or do we have to conceive of them as based on regularities and conventions? What is an adequate model of the acquisition of the skills which are relevant for mastering the inferential processes leading to an adequate interpretation of utterances? And what is the relation between a theory of pragmatic enrichment and optimality theory with an OT pragmatics as a possible result?

The testis is composed of seminiferous tubules and interstitial tissue. The most important component of the interstitial tissue are the testosterone-producing Leydig cells. The seminiferous tubules contain the successive generations of germ cells, which can only exist in the presence of Sertoli cells. Sertoli cells mediate the effect of testosterone, which is indispensable for the maintenance of spermatogenesis. Consequently, the function of the Sertoli cells depends large lyon the function of the Leydig cells, and a local control mechanism between the two cell systems has been assumed. Sertoli cells are supposed to interfere with the regulation of Leydig cell hormone production (Aoki and Fawcett 1978; Sharpe et al. 1981). Few cell types of the testis have received as much attention in recent years as have the Sertoli cells. While comprehensive data had accumulated concerning the differentiation of germ cells, there was formerly little information available on the influence of Sertoli cells on this process. Only through recently developed methods and experimental approaches could their central role in spermatogene sis be verified. Sertoli cells are the only somatic cells in the seminiferous tubules. Their origin is still disputed (for references see Ritzen et al. 1981). They supposedly stem either from the coelomic epithelium or from mesenchymal cells of the genital ridges. According to Wartenberg (1978) they are derived from a gonadal blas tema containing cells from both the coelomic epithelium and the mesonephros."