An experiment in comparative developmental aspect was carried out with 5 horses and 5 cattle having a total of 60 skin and muscular wounds. Light microscopic studies on hematoxylin-eosin stained preparations revealed that the dystrophic changes in the underlying tissues were more strongly manifested in horses. This had to be taken into consideration in the surgical treatment of wounds with this animal species. The basic differences comprised the better manifested leukocytic reaction in horses and the more strongly expressed processes of growth and differentiation on the part of the connective tissue after the tenth day of wounding in cattle. The definitive formation of granular tissue in horses took place in shorter terms than in cattle. In the fully developed new tissue in horses three different layers were found: leukocytic, vascular-fibroblastic, and a maturing one, while in cattle the layers found were four: fibrous tissue, heterophilic-leukocytic, vascular-fibroblastic, and a maturing one.