12 HARRY WARREN* ANDERSON 



MORPHOLOGIC, PHYSIOLOGIC, AND CULTURAL STUDIES OF ORGANISMS ISOLATED 



The 113 organisms isolated were grown on a number of mediums in order 

 to make a preliminary separation into groups on the basis of striking dif- 

 ferences. For comparison, the determined organisms given in Table 2 were 

 obtained from various sources. In addition to these a number of undetermined 

 species isolated from the gastric residua of normal persons was furnished 

 by Mr. Max Levine of Iowa State College; organisms which are of special 

 interest on account of their source. Several cultures of species of Mycoderma, 

 Torula, and Monilia, indicated by number only, were received from different 

 laboratories. Cultures isolated from different fruits during the course of this 

 study were also used for comparison, as was also Sclerotinia (Monilia) cinerea 

 isolated from plum. Dr. Simon also kindly sent me the organism described 

 by him as causing a tuberculous condition of the lungs. Blastomyces derma- 

 titidis was obtained from the Memorial Institute of Infectious Diseases in 

 Chicago and from the American Museum of Natural History. Thus, in all, 

 over 160 cultures were used in the preliminary study of the group of budding 

 fungi. While only a limited number of these were studied in detail, a series 

 of comparative observations was made on the entire series. As the result of 

 a preliminary study the organisms isolated were separated into a number of 

 large groups which are described. 



Variation in color furnished the first basis of separation. There appeared 

 in a large number of the original plates pink or red colonies of yeasts which 

 made gelatinous watery growths and appeared very similar in gross characters. 

 Isolations of these were not attempted except in about half the first samples 

 tested, since it was early decided that most were of the same species. When- 

 ever a variation in these pink colonies was observed, such as shade of color, 

 type of growth, or shape of cells on microscopic examination, the form was 

 isolated and saved for future comparison. Four types of red or pink yeasts 

 were thus obtained which will be referred to only as Types 1-4 since this 

 paper includes a specific study of only 1 of these. 



The 2nd group, on the basis of color, included those of a chalky-white 

 appearance on agar slant cultures. These constituted the largest percentage 

 of yeasts isolated and it is with this group that I am now especially concerned. 



The 3rd group develops a yellow, golden, or gray colony on agar plates. 

 This is a miscellaneous group for the inclusion of all the odd forms not 

 included in the first 2 groups. It is especially important, however, since many 

 of the so-called pathogenic yeasts are of this type. Only 2 isolations of 

 this type were made but several of Levine's yeasts from normal stomach con- 

 tents belong here. Most of the yeasts of this type liquefy gelatin and develop 

 more or less of a slimy growth on most mediums. These 3 groups will be 

 designated as the 'pink', 'white', and 'golden' groups. 



The white group, on account of the number of forms isolated and their 

 similarity to most of the important pathogenic yeasts described in the literature 

 as 'Monilia' and 'Oidium' species, were made the object of special study. This 

 group could be subdivided into 2 very distinct subgroups: (1) those which 

 form a slightly to decidedly heaped, glistening growth, especially in young 

 slant cultures, and (2) those which form a spreading, dull-white growth on 

 agar slants and usually produce a heavy, dry pellicle within 48 hours on liquid 

 mediums. The latter type will be designated the 'Mycoderma' type since this 

 characteristic growth is the basis of the formation of this genus according to 

 Hansen, Will, and others. 



