Mandatory reading for anyone doing a STAT course, a bit odd for anyone else, unless they're having lessons and want to know a bit more about Mr. Alexander.
Written before DNA was discovered, it is predicated on a misconception of how evolution operates, and there's a fair degree of racial predjudice (he didn't like Germans and considered some races primitive)... but that's got more to do with the prevailing attitudes of the time than the man himself. What it shows about him, is an enquiring mind and a devotion to improving the lot of our species.