78 CULTURAL STUDIES OF SPECIES OF PENICILLIUM. 



acid 0.9 per cent, fair growth, not good. Levulose 3 per cent, good but slow colo- 

 nies, acid reactions. Glycerin 3 per cent, medium growth, pink tinge to fluid. Potato 

 starch 3 per cent, good growth, yellow drops of transpired fluid, fluid tinged yellow 

 at top only. Butterfat, rich growth, fluid reddish brown. 



Milk, good growth, acid in litmus milk; curdling (0.25 per cent calcium chlorid 

 added) in 8-9 days, good curd; digestion slow, incomplete; color, pale yellow in 

 digested fluid. 



At 37° C, killed; check at 20° C, good. 



SPECIES FORMING PINK SCLEROTIA. 



Four races have been found in which pink sclerotia are regularly 

 formed in culture. These sclerotia are elliptical to globose and 

 from 200 to 500/f in diameter. They begin to be formed within the 

 first week in richly nourished cultures. Although examined repeat- 

 edly, no trace of ascus formation has yet been found. These forms 

 are included here under their serial numbers, 29, 30, 31, and 32, 

 rather than with specific names. The descriptions and figures 

 introduced will, it is thought, identify these organisms clearly in 

 their penicillium form, but the uniformit}^ of sclerotium "production 

 makes ascus production so probable under proper conditions that 

 it seems best not to give specific names to this imperfect form when 

 some of them may be already recognizable by others or by further 



investigation. 



Penicillium No. 29. 



Colonies grown upon gelatin and potato or bean agar white to gray-green, sometimes 

 partly clear green, becoming zonate with rings of pink sclerotia in age, sparsely or 

 loosely floccose, indeterminate broadly spreading margins persistently white, slightly 

 yellow below. Conidiophores 80-200// or even 400/t by 3-5/z commonly 150-200/t 

 in length as branches, usually perpendicular, from hyphse 4-5/i in diameter. Co- 

 nidial fructification a single verticil of rather few (about 12-15) conidiiferous cells 

 9 by 2/i, producing chains of conidia in a loose column 150-250/* or even 400/t by 20- 

 30/i. Conidia elliptical, 3-3.6 by 2.3-2.8/t, smooth, very pale blue (transmitted 

 light) . Sclerotia in loose networks of mycelium, numerous, pink, elliptical to globose, 

 150-300/z in diameter. These begin to appear in one week in gelatin cultures. Colo- 

 nies liquefy sugar gelatin slowly but completely in 10-12 days. Give a strong acid 

 reaction with litmus media. 



Characterized by the production of large numbers of pink sclerotia with compar- 

 atively small quantities of conidia, whereas the next form (Penicillium No. 30) pro- 

 duces few sclerotia and great quantities of conidia. 



Collected at Storrs, Conn., on decaying mushroom. Probably not closely related 

 to the common species of Penicillium, but its occurrence in culture and ready adap- 

 tation to all media tried, in numerous cultures, justify its inclusion with these species. 



CULTURAL DATA. 



Color white to gray or green, with many pink sclerotia; reverse colorless or slightly 

 salmon; color in media slightly yellow in some media. 



Odor, none. 



Fifteen per cent gelatin in water, good growth; liquefaction, 15 days; litmus reac- 

 tion alkaline. Potato agar and bean agar, typical colonies, white or gray, with. few 

 green areas and abundant pink sclerotia. Raulin's fluid, typical. Colonies upon 



