l'KMi II.LIC.M DIGITATUM. 31 



In bis discussion of this fungus Wehmer S1 shows thai the blue-green 

 i -. * t of citrus fruits is a differenl species from the similarly colored 

 apple rot. His description seems to l>e the first recognition <>l this 

 species as differenl from the green molds occurring constantly upon 

 all kinds of food. This species has been discussed as P.glaueum in 

 recent papers i K. E. Smith, 2 ' Powell 20 ), \\ here its agency in the decay 

 of oil ins fruits is \ei\ fully considered. 



Cultures were obtained by the writer from oranges in Hanover, 

 Germany, and identified by the describer, Dr. C. Wehmer. It has 

 since been repeatedly observed and collected in America. Pure cul- 

 tures <-an always l>e secured by finding decaying oranges in the mar- 

 ket which have the blue-green areas of rol just beginning to appear 

 upon them. These areas are usually blue-green in center surrounded 

 by white areas which are usually grouped into little white patche 

 toward the vegetative margin and the whole superficial colony sur- 

 rounded by an area of soft, watery rot. Xrry often such colonies 

 when older become much contaminated with the olive-colored rot, 

 given in this paper as P. digitatum. 



CULTURAL DATA. 



Color, dear bluish-green mi sugar media, shades of gray-greeD without sugar; reverse 

 of colony commonly brownish in areas; color in media none or slighl . 



Oder distinct upon media containing cane Bugar, uone on lactose or media free from 

 sugar. 



Fifteen percent gelatin in water, medium growth; Liquefaction, none until several 

 weeks old, then partial in acidified cultures; litmus reaction fairly alkaline. Potato 

 agar « Lth lactose, rather thin gray-green colonies, not vigorous, acid reaction, retain 

 plugs, pale but characteristic. Raulin's fluid, typical colonies. Cohn's solution, 

 germination onlj . 



Synthetic fluid I 1 >e\ V , carbon supplied as: < lane sugar, good colonies up to 50 pei 

 ■ ■en i wiih alkaline reaction. 1. act use :; per cent, slew growth bu1 typical, with acid 

 reaction. Lactic acid 9 per cent, small growth. Levulose ■'> per cent, not normal. 

 Galactose 3 per cent, medium growth, acid reaction. Glycerin 3 per ecu i . no growth; 

 growth began when sugar was added. Butterfal , growth slow. 



Milk, good growth: curdling (0.25 per cenl calcium chlorid added ), ten days; diges- 

 tion partial and -low; color bIowIj brownish <>r yellow-brown. 



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



PENICILLIUM DIGITATUM Saccardo. 



The olive-green orange rot, /'. digitatum Sacc, in Mycotheca Italica, No. 986, Ber- 

 barium U.S. Department of Agriculture; in Sylloge Fungorum, Vol. [V, p. 79; in 

 Fungi [talici, No. 894. 



= /'. olivaa urn Wehmer, Beitr. z. Kennt. einheim. Pilze, pp. 73, t. [I, Jena, I 

 "iMucor exspitosus 1... in Species Plantarum (1753), 11, p. list;, based upon 



Micheli, tab. !U, lig. :'.. 

 7 Manilla </i</ii(ihi Fries, Sj sterna Mycologicum, 1 1 1 , p. ill. 



Colonies on .-agar gelatin ami potato or bean agar grayish olive, irregularly shaped 



from the unequal growl h and branching of rather few hypha . aerial port ion consisting 



only of very short conidiophores and conidia. Reverse of colony commonlj shows 

 brown to black colors. Conidiophores rising directrj from the substratum, 30 100 by 



