Meshwork cells from the bovine outflow system were grown in culture and their growth characteristics and behaviour in vitro reported. The cells were studied by inverted phase microscopy and time-lapse cinephotomicrography. It was found that plating efficiency was highest for third and seventh passage cells. These cells reached confluence within 2 weeks when plated out at 7.5 X 10(3) cells cm-2 in a conventional culture medium containing 10% serum. Third passage cells were studied in greatest detail. These cells exhibited postconfluence contact inhibition of division. By 2 weeks postconfluence the division rate decreased 10-fold to a level of less than six divisions per thousand cells per day. The contact inhibition was not overcome by increasing the serum content of the medium. On the other hand, a 30-fold increased division rate could be produced after scratching the culture flask. Postconfluent contact-inhibited cultures were considered to be a better reflection of the behaviour and activities of meshwork cells in vivo than cultures which retain a high level of division.