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Production of spermatozoa and secretion of rete testis fluid (RTF) in rams was assessed by a rete testis cannulating technique. Four breeds (Ile-de-France, Romanov, Préalpes du Sud and cross-breed Romanov) were studied throughout the year. Inhibitory effects of the cannulation process on spermatogenesis were observed for some animals. Between-breed differences were found in sperm concentration and flow rate of the RTF. The seasonal variations in the daily sperm production of the testis were more pronounced for Ile-de-France rams than for the other breeds. There was a seasonal variation in the flow rate of RTF in Ile-de-France rams, the minimum flow being in February (winter) and the maximum in August-September (autumn).

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Consequently, a new terminology has arisen. It is used by different authors, in different languages, so that in context it has a different and sometimes opposite meaning to the old more classical nomenclature. Even if problems still remain to be clarified before a definitive understanding of the spermatogenic process is reached, the terminology should be standardized at least for the purpose of teaching students in the medical and allied areas. At the same time this would allow incorporation of the new advances that research in this field provides.although not exhaustive, aims at: 1. surveying of current concepts 2. compiling of the more important facts and problems 3. and thus facilitating discussion among those interested in this area of research.In the classical literature, the term "spermatogenesis" designates the development of the primordial germ cells of the embryo up to the late spermatids which are released by the germinal epithelium in the adult seminiferous tubules (spermiation). The concept of the continuity of spermatogenesis and what we consider to be a useful nomenclature are presented in Fig. 1. Many of the steps are tentative because of the present lack of adequate knowledge. Thus, this schematization should be regarded as an operational proposition to stimulate further research and discussion.Today, most text-books use the word "spermatogenesis" to imply the proliferation, maturation and differentiation of the germinal cells in the adult. For the English-speaking authors, spermatogenesis is thus the sperm production after puberty, comprising spermatocytogenesis, meiosis and spermiogenesis (Bloom and Fawcett -1968). Most of the problems in terminology arise from the fact that information concerning the development of the germinal cells in the prenatal and prepuberal stages is scarce. Authors dealing with this particular field of research have advanced new terms, for example, Hilscher (1973) speaks of: 1. Pregonadic stage, up to the migration of the primordial germ cells into the gonadal anlage, 2. Prespermatogenesis up to the appearance The present review on mammalian, including human, spermatogenic processes,