1. An introduction to the subject of medical mycology is
given with a brief indication of its scope and the organisms
concerned. The nature of the Experimental Mycoses Unit is
described and the objects of the present work defined.
2. The first part of the work is a survey of the fungi occur -1
:ring in a variety of human sources, with especial reference to the
yeasts. 1,004 samples were examined from urine, sputum, throat,
high vaginal, wound, stool and other sources. 289 fungi (28.8%) were obtained; 248 (86%) of the isolates were yeasts.
3. Candida albicans was the most common species and was
isolated on 141 occasions (56% of the total number of yeasts).
Other species were Torulopsis glabrata (31); Rhodotorula mucilaginosa
(16); Candida tropicalis (12); Candida parapsilosis (7);
Saccharomyces cerevisiae (4); Candida zeylanoides (4); Cryptococcus
albidus (4); Saccharomyces fragilis (3); Candida krusei (3);
Hansenula anomola (2); Pichia membranaefaciens (2); Saccharomyces
carlsbergensis (1); Trichosporon cutaneum (1); Candida robusta (1)i
Candida guilliermondii (1); Torulopsis famata (1); Torulopsis
candida (1); Cryptococcus laurentii (1); Cryptococcus diffluens (1).
4. Torulopsis glabrata is shown to be a significant member
of the flora of the sources examined.
5. A description of 11 isolates which were atypical is given
with a discussion on their taxonomic affinities.
6. Rhodotorula mucilaginosa was obtained from decaying
vegetation; Candida guilliermondii was isolated from soil.
7. A description is given of a strain of Candida tropicalis
which was responsible for a fatal septicaemia.
8. An evaluation of the methods used in the survey is
9. Tissue culture techniques were used to demonstrate
phagocytosis of Candida albicans and Candida tropicalis.
10. In vivo experiments showed that Candida albicans rapidly
forms pseudomycelium. After 12 hours verticillate branching occurs. An association between branching and the presence of polymorpho-
:nuclear leukocytes is indicated. Candida tropicalis also forms
pseudómyycelium in vivo, but a check is evident after 4 hours.
Pseudomycelial strands are branched and production of blastospores
is not entirely suppressed.
11. Blastospores of Torulopsis glabrata were predominantly
intracellular within host phagocytes after 12 hours.
12. Abortive pseudomycelium is demonstrated in Saccharomyces