Study of the esophageal microscopic morphology of adult Rana perezi by light and electron microscopy discloses some large folds throughout the esophagus that are in themselves ringed. Glandular ostia open in the furrows of the luminal surface. The esophageal wall is made up of a connective adventitia rich in melanocytes, a muscular tunica, a connective and glandular subepithelial layer, and a pseudostratified ciliated epithelium. This epithelium basically consists of ciliated, goblet, basal, microvillous-apex, and migratory cells. Two types of goblet cells are distinguished with regard to the granular ultrastructure. The microvillous-apex cell has not been found in other amphibians. It shows a very differentiated morphology with a high number of mitochondria. The basal cells give the epithelium a pseudostratified morphology, and they have a proliferative function. Glands are branched and drain through an excretory duct that has a monolayered mucosecreting epithelium. The glandular units are formed by two principal types of cells: mucosecretory and serous.

A histochemical study was carried out on the glycoconjugates of the nasal mucosa of rat and guinea pig using conventional techniques and peroxidase-labelled lectins. Both the respiratory mucosa and neuroepithelium were studied. Sulphate and sialic acid groups were found in the mucous layer of the neuroepithelia, Bowman's glands and goblet cells. In contrast, the nasal glands did not possess these groups, and only a few showed neutral mucins. Carbohydrate residues were more numerous in the acini of the Jacobson glands. Thus, the nasal glands in the rat and guinea pig are probably of a serous type because of the scarcity of carbohydrate residues.

The morphology of the spermatozoa in the cauda epididymidis of 6- and 24-month-old (adult and aged) hamster was studied by electron microscopy. Lesions found in the spermatozoa included alterations in the acrosomal matrix and nuclear membranes, abnormal or absent mitochondria, alterations in the axonemes, dense fibres and microtubules, and bent flagella. All these abnormalities are similar to those found in other species and few alterations were exclusive to the older animals. Ultrastructurally abnormal spermatozoa were observed in both groups but were present at a significantly greater frequency in aged hamsters (p < 0.005). The percentage of sperm with abnormal acrosomes, mitochondria and dense fibres and of bent (but not disrupted) spermatozoa was significantly greater in the older animals. These results show that the ultrastructural alterations in hamster sperm are similar to those found in other mammals. Moreover, the percentage of ultrastructurally abnormal spermatozoa in aged hamsters is greater than 6-month-old hamsters, this increase is not accompanied by any new kinds of alteration.