The rabbit defense system has a number of specific features: no lactoferrin and lysozyme are detectable and peroxidase activity is only demonstrated in the cubic epithelial cells of the ducts. Experiments carried out with radioactive amino acid, demonstrate the absence of secreted proteins with molecular weights corresponding to those of albumin and transferrin, indicating that these proteins are not synthesized by the lacrimal gland tissue. Rabbit tear pattern presents a set of acidic proteins secreted by the lacrimal gland tissue, with small molecular weight and acidic pl's.