Comparative histometric study in the aortic arch of birds.

A histometric method was here adopted to study the concentration of elastic and collagenous fibers, muscle cells and cellular population of the mesarteria of the middle portion of the aortic arch of several species of birds were studied. The statistical analysis consist of the F test followed by Snedecor 's contrast test. The results obtained show that the concentration decrease on the sequential order of: fibers elastic, muscle cells and collagenous fibers in the goose, duck, black-culture and turkey, while in the peking duck the collagenous fibers were in more amount the muscular tissue, but not exceed the elastic fibers. From the variations pointed out here for the differents elements studied, only those of the muscular tissue have demonstrated a relative statistical signification.