THE USE of animals in biologic experiments should be based on (1) perfect orientation as to the normal anatomy and histology of the animal in question and (2) knowledge of pathologic conditions arising without experimental interference. Previous studies1 concerning the rat have shown that, while anatomic relations are far from being sufficiently explored, the nonexperimental pathologic processes, though generally known, are widely disregarded. In the rat, these two circumstances combine well nigh to demolish the cornerstone of experimental work—the idea of the so-called control animal.
Available data on gross anatomy lag behind those regarding histology. Competent information about the elements of the mucous membranes, respiratory and olfactory, is available, but no survey has been made on detailed anatomy of the nasal cavity of animals in daily laboratory use. In older monographs little attention was paid to the needs of the laboratory worker; even so, data found in them are