262 JOURNAL OF THE SOCIETY OF COSMETIC CHEMISTS Vaginal secretions 60 40 .• zo '• o I'--I • A/ 69 62 ._ ._u_ Synthetic mixture I 40 N 77 69 0.6 0'4 • 0.2 '5 0 (. , .•, .• 0.6- õ 0.4 0.2 7 69 62 c ø' 69 62 ._ 77 69 77 69 Pre- Treatment Pre- Treatment Pre- Treatment treatment treatment treatment Figure $. Comparison of the effectiveness of vaginal secretions and synthetic pheromones on the sexual behaviour of male rhesus monkeys. Treatment using both methods produced a significant response, but vaginal secretions were more effective than synthetic pheromone. males' sexual activity as the original vaginal secretions. This could mean there is a component in untreated secretions that is lacking in the synthetic mixture. Phenylpropanoic (PPA) and parahydroxyphenylpropanoic acids (HPPA) are both odorous compounds identified in the rhesus monkey's vaginal secretion, but are quite ineffective in stimulating male sexual activity when applied alone to the sexual skin area of an ovariectomized female partner. By addition of PPA and HPPA to the synthetic acid mixture an enhance- ment of the effectiveness of synthetic pheromone has been obtained (Fig. 5). Sexual interactions were shown by the male in more tests (65•o) than when just synthetic mixture of acids alone were applied (37•o of tests). The mixture containing enhancers was almost as effective as the untreated vaginal secretions (70•o of tests), although the amount of sexual behaviour stimulated was not so high. Untreated vaginal secretions when applied to the sexual skin of ovariectomized females in this test series stimulated 252

SEX ATTRACTANTS IN PRIMATES 263 IOO 6o 2o o N 100 2O v•ale 41 67 68 113 6 5 7 5 20 26 22 24 Zemale 76 74 78 21 26 7 8 71 23 22 ]•] Vaginal secretians •'• Synthetic pheramones Figure 4. Variability in the response of different males to vaginal and syn- thetic pheromones and their relative effectiveness when applied to different female partners. 80 .• 6o ,• 40 .•_ -- • 20 -• 0.75 B 0,5 -•. e- • 0.25 0 20 69 20 0 N 20 69 20 • 12 0-- 20 69 20 I-• Vaginal secretions [• Synthetic pheromones i:i• Synthetic pheromones+PPA and HPPA Figure 5. Improvement in the effectiveness of synthetic pheromones when phenylpropanoic and parahydroxyphenylpropanoic acids are added.