Penis
Domestic cats have barbed penises, with about 120–150 one millimeter long backwards-pointing spines. Upon withdrawal of the penis, the spines rake the walls of the female's vagina, which is a trigger for ovulation. Lions also have barbed penises. Male felids urinate backwards by curving the tip of the glans penis backward. When male cheetahs urine-mark their territories, they stand one meter away from a tree or rock surface with the tail raised, pointing the penis either horizontally backward or 60° upward.
History of anthropometry
Several studies have demonstrated correlations between race and brain size, with varying results. In some studies, Caucasians were reported to have larger brains than other racial groups, whereas in recent studies and reanalysis of previous studies, East Asians were reported as having larger brains and skulls. More common among the studies was the report that Africans had smaller skulls than either Caucasians or East Asians. Criticisms have been raised against a number of these studies regarding questionable methods.
In "Crania Americana" Morton claimed that Caucasians had the biggest brains, averaging 87 cubic inches, Indians were in the middle with an average of 82 cubic inches and Negroes had the smallest brains with an average of 78 cubic inches. In 1873 Paul Broca (1824–1880) found the same pattern described by Samuel Morton's "Crania Americana" by weighing brains at autopsy. Other historical studies alleging a Black-White difference in brain size include Bean (1906), Mall, (1909), Pearl, (1934) and Vint (1934). But in Germany Rudolf Virchow's study led him to denounce "Nordic mysticism" in the 1885 Anthropology Congress in Karlsruhe. Josef Kollmann, a collaborator of Virchow, stated in the same congress that the people of Europe, be them German, Italian, English or French, belonged to a "mixture of various races," furthermore declaring that the "results of craniology" led to "struggle against any theory concerning the superiority of this or that European race". Virchow later rejected measure of skulls as legitimate means of taxonomy. Paul Kretschmer quoted an 1892 discussion with him concerning these criticisms, also citing Aurel von Törok's 1895 work, who basically proclaimed the failure of craniometry.