124 JOURNAL OF THE SOCIETY OF COSMETIC CHEMISTS Resident Flora Yeasts--A total of 31 different strains of yeasts was isolated. One of these was a pink yeast which was lost in subculture and one was P. ovale. Neither P. ovale nor P. orbiculare was included in the following study because they have been considered previously by direct smear examination. All lost or unidentified microorganisms were included and were so indicated. Four different species of yeasts were identified. They are listed in Table IV. A total of 44.2% of all subjects had yeasts, ranging in number from one to three different species per individual. In those subjects having no dandruff but harboring yeasts, the average number of yeast species was 1.1 per person, as compared to 1.4 species per person in those subjects Table IV The Prevalence of Resident Yeasts Isolated from the Scalps of 52 Subjects Number of Percentage Yeast Isolate Isolates of Subjects Rhodotorula mucilaginosa 13 25.0 Candida parapsilosis 12 28.1 Rhodotorula minuta 3 5.8 Trichosporon cutaneum 1 1.9 Table V The Prevalence of Resident Molds Isolated from the Scalps of 52 Subjects Number of Percentage Mold Isolate Isolates of Subjects A•pergillus awamori 51 98.1 Aspergillus fumigatus 42 80.7 Pullularia pullulans 8 15.4 Aspergillus fiavus 7 13.5 Penicillium notatum 5 9.6 Aspergillus terricola var. americana 5 9.6 Alternaria tenuis auct. sensu str. 3 5.8 Helminthosporium trisep- tatum 3 5.8 Stemphylium sarciniforme 2 3.8 Penicillium chrysogenum 2 3.8 Penicillium commune I 1.9 Penicillium implicatum I 1.9 Penicillium lilacinure I 1.9 Aspergillus nidulans I 1.9 Aspergillus terreus I 1.9

FLORA OF SCALP AND DANDRUFF 125 with dandruff. Only 29.2% of the subjects without dandruff had yeasts, but yeasts were found in 56.4% of those with scurf weights over 40 mg. The two most common yeasts were more prevalent on subjects with dan- druff than on those without dandruff. •Rhodotorula mucilaginosa oc- curred in 28.6% of subjects with dandruff and in 20.8% of those without dandruff. C. parapsilosis was isolated in 32.2% of those with scurf weights over 40 mg but only in 8.3•0 of those with less than 40 rag. Molds--Molds were found in 100•o of the subjects. The number of species varied from one to seven per individual. Those subjects with dandruff averaged 3.1 species of molds each, whereas those without dan- druff averaged 2.3 species. Of the 143 molds isolated, 133 were identified to species. The remaining ten molds included three species of •Penicil- lium, four species of Cephalosporium, two species lost in subculture, and one unknown genus. Six genera were represented: ,4spergillus, Penicillium, Pullularia, .4 Itemaria, Stemphylium, and Helminthosporium. The species of Aspergillus were identified according to the methods and media of Raper and Fennell. (37). The keys of Raper and Thom (38) were used to identify the species of Penicillium. Colors of colonies in both genera were compared to the descriptions and standards of Ridg- way (39). According to Ainsworth (40), there is only one species of Pullularia, Pullularia pullulans. This species corresponded to the de- scription given by Barnett (41). Alternaria and Stemphylium were classified according to the media and methods of Neergaard (42). A key by Luttrell (43) was used to identify the tlelminthosporium. Fifteen species of molds were included in six genera and they are listed in Table V. The prevalence of the four most common resident species of molds from subjects with and without dandruff is summarized in Table VI. Table VI The Prevalence of the Four Most Common Resident Molds in Persons with and without Dandruff Mold Isolate Percentage Pel centage of Subjects of Subjects with without Dandruff Dandruff Aspergillus awamori 100 95.8 Aspergillus fumigatus 67.9 95.8 _Pullularia pullulans 28.6 ... Aspergillus flayus 14.3 8.3