thought were lymphatic vessels, seemed to bloom from the "glandulae," running toward the pia on one side and penetrating dural layers on the other. Therefore, he concluded that his "glandulae" (glands) had the function of secreting lymph to lubricate the sliding movements between brain and meninges during contractions. Although these speculations appear grossly incorrect in the light of present knowledge, new observations seem "to do justice" to Antonio Pacchioni. In a recent study, Go, et al., ~ using enzyme ultracnytochemistry, detected Na+/K + adenosine triphosphatase activity on cap cells of arachnoid villi; they proposed that this biochemical mechanism could contribute to CSF absorption. This assumption implies a "'secretory" component in CSF absorption along with the already widely accepted mechanisms. It is remarkable to note that, if this single observation is confirmed, we may have to look at arachnoid villi not simply as hydrostatic pressure-gated valves, but as actual secreting structures: that is, as glands or "glandulae," as Antonio Pacchioni suggested three centuries ago. Works (Books are kept at exclusive libraries such as the Harvard Medical Library) Enrico Benassi: Carteggi inediti fra il Lancisi, il Pacchioni ed il Morgagni. Rivista di storia delle scienze mediche e naturali, 1932, 23: 145-169. Maria Bertolani del Rio: Antonio Pacchioni 1665-1726. In, Luigi Barchi, editor: Medici e naturalisti Reggiani (Reggio nell' Emilia), 1935: 659-667. Pietri Capparoni: Lo stato di servizio di Antonio Pacchioni all'Ospedale della conzolazione in Roma ed un suo medaglione onorario. Rivista di storia delle scienze mediche e naturali. 1914, 2: 241-245. Jacopo Chiappelli: Notizie intorno alla vita di Antonio Pacchioni da Reggio. Raccolta d'opuscoli scientifici e filologici, Biblioteca Modenese, Modene 1783, III: 415-419. Bibliography References 17th-century Italian physicians 18th-century Italian physicians Italian anatomists 1665 births 1726 deaths