On the other hand, we have the remarkable tenacity to custom and habit in this regard, as exhibited by the Moslems, who, although having neither ordinance nor authority for its performance, either in their law, creed, or in any order from their prophet, still no more zealous circumciser exists than the son of Islam, who exacts from all proselytes the excision of the prepuce. Mohammed was circumcised in his boyhood, and, although he did not order its performance to his followers, he did not see fit to proscribe a custom so general to the Arabians, where the greater development of the prepuce probably renders circumcision a necessity. From the same reason it is easy to perceive why the rite has found such general observance among the Africans, who are as noted for long and leathery prepuces as for their slim shanks. One author, writing in 1772, in a work entitled "Philosophical Researches on the Americans," treats the subject in a very intelligent manner. His arguments are both ingenious and plausible. This author looks upon circumcision as of purely climatic origin in its inceptive causes. From a careful survey of the natural history of man in his general distribution over the globe, he finds that circumcision may be said to be restricted to within certain boundaries of latitude, equidistant on both sides of the line. No circumcised people have ever inhabited northern regions, and the bulk of the circumcised races are found within certain climates. From this reasoning it is easy to see why the rite should lose its standing under certain climatic conditions, unless bolstered up by some religious significance, as it is equally easy to foresee why it should flourish elsewhere, even without any religious backing or ordinance. It is well known that in Ethiopia and the neighboring countries, excrescences and elongation of either the prepuce or nymphae are as probable as the existence of an enlarged thyroid gland or goitre among the inhabitants of some of the valleys of Switzerland or of those of the Tyrol. According to the author of the treatise just quoted, circumcision would be nothing more than a remedy to repair the evils that a faulty construction of the human body developed in certain climatic conditions.