[On acclimatization: Boudin and medical geography].

In order to understand the medical geography studies by Boudin, we analyze the differences that set him apart from the acclimatization theories defended during that same historical period by Isidore Geoffroy Saint-Hilaire. Each one of them represents a paradigmatic position in relation to the problem of acclimatization. To understand the difference between these models, we analyze the concept of climate (from Humboldt) undertaken by both as a starting point for their studies, and consider their thoughts on organism variability or flexibility to respond to climatic requirements. This leads us to a study on Boudin's thoughts on the acclimatization of humans and races, and consequently, his thoughts on the colonization issue.