All right? He was perplexed by the sexual swellings of certain primates, including chimps and bonobos, because these sexual swellings tend to provoke many males to mate with the females.
Giusto? Lo lasciavano perplesso i gonfiori sessuali di certi primati, compresi scimpanzé e bonobi, perché i loro gonfiori sessuali  tendono a spingere molti maschi  ad accoppiarsi con le femmine.