32 CULTURAL STUDIES OF SPECIES OF PENICILLIUM. 



4-5/t, usually very short. Conidial fructification a few tangled conidial chains up to 

 160/t in length, borne upon conidiiferous cells 13-16 by S-4pt. Conidia cylindrical to 

 almost globose, 4-7 by 6-8/t (at times 6 by lO/i), often uneven in size and shape in the 

 same chain. Colonies do not liquefy sugar gelatin except at times partially in cultures 

 three weeks old or more. Litmus reaction acid. Grows readily on organic media, but 

 shows a very pronounced affinity for such media with high percentages of sugar, in 

 which it produces a strong odor. Refused to grow in synthetic media containing nitro- 

 gen as sodium nitrate. 



Cosmopolitan upon citrus fruits, distinguished from P. italicum by the sharp con- 

 trast of its olive color with the blue of the other. Collected in Hanover and verified 

 by Dr. C. Wehmer. Received from Prof. P. H. Rolfs in Florida. Seen upon decaying 

 oranges everywhere. Pure cultures can always be secured from the common market 

 fruits. 



Nomenclature. — Wehmer 31 (1895) gives the first adequate discus- 

 sion of the decay of citrus fruits by the agency of species of Penicil- 

 lium in which the forms found were shown to be distinct species 

 associated constantly with these fruits instead of common green 

 species accidentally occurring upon these fruits. For the olive- 

 green form the name proposed, P. olivaceum, is descriptive, but had 

 already been used by Corda (Icones, III, p. 12, t. II, fig. 35) for 

 a species afterwards transferred to Ilormodendrum. The name 

 P. olivaceum Wehmer is therefore not tenable by present rules of 

 nomenclature. 



P. digitatum is the name used by Saceardo, as is shown b}^ the 

 specimens distributed by him (Mycotheca Italica, No. 986) previous 

 to Wehmer 's work. In his description and synonymy he cites the 

 name from Fries (Systema Mycologicum, p. 411), where it appears as 

 Monilia digitata, transferred by Saceardo to Penicillium. But Fries 

 cites his use of the name from Persoon l0 (Synopsis Fungorum, p. 693), 

 who bases his description of Monilia digitata upon Micheli's 14 figure 

 and description (Nova Plantarum Genera, p. 213, pi. 91, fig. 3). 

 Here, under the name of Aspergillus, Micheli figures and describes as 

 No. 8 a fungus which may be taken for a Penicillium, which is said to 

 have been found upon semi-putrid lemons. This figure is cited by 

 Linnaeus in Species Plantarum (1753), II, p. 1656, as the basis of his 

 Mucor csespitosus. 



If we accept Saccardo's citations as correctly giving the origin of 

 the name and tracing it back to Micheli, we must abandon the name 

 he uses and adopt the name given by Linnaeus — Mucor csespitosus = 

 P. csespitosum (L.). Careful scrutiny of Micheli's figure gives no 

 possible means of identification. Aside from identification from pre- 

 served specimens which are not cited by the authors in any case, 

 there is little possibility of showing what any of the authors com- 

 monly cited, for this species may have had until we come to the 

 description given by Saceardo in the Sylloge (IV, p. 79), and the 

 material distributed by him in Mycotheca Italica, which I have seen 

 and which is certainly this fungus. I have therefore continued the 

 use of Saccardo's name in this case because he has given the first 



