(1) Using autoradiography, substantial and comparable concentrations of labeled molecules were detected in the mouths, VNO ducts, and VNOs of normal subjects in both conditions, as well as tongueless lizards whose snouts made physical contact with swabs.
(2) Temporary blind and anosmic conditions did not have a significant effect on response rates of the tongueless or control groups.
(3) Feeding, as well as responses to prey extracts, were found to be suppressed almost totally in the tongueless naive snakes.
(4) No label was evident in VNOs of tongueless animals that did not contact swabs or normal animals with sealed VN ducts.
(5) To test this hypothesis, a cotton swab soaked in prey extract mixed with [3H]proline was touched ten times to the snouts of normal and tongueless lizards (Chalcides ocellatus), as well as normal lizards whose vomeronasal organ (VNO) ducts had been sealed with a tissue adhesive.
(6) Additionally, such a swab was held approximately 0.5 cm in front of the snout of normal and tongueless lizards for 1 min, which allowed no contact by tongueless animals and tongue contact only by normal lizards.