MONOVERTICILLATA 183 



what intermediate character are often encountered among large groups of 

 isolates, and these tend to bridge between the two species. Such varia- 

 tion may occur either in colony texture and character, in details of struc- 

 ture, or in the colony reverse. Individual strains are placed in either one 

 species or the other upon the basis of their more obvious relationships. 

 Variation from P. sjpinulosum may also occur in the direction of the P. 

 lividum series. Penidllium trzebinskii Zaleski, characterized by deeply 

 velvety colonies and conspicuously elliptical conidia, is regarded as repre- 

 senting an extreme example of such variation. While this species is cur- 

 rently placed in the P. lividum series (see p. 189), its possible relationship 

 to P. spinulosum is well recognized. 



A number of species, more or less fully described by other investigators. 

 are believed to belong with Penidllium spinulosmn Thom as this species 

 is considered here. Strain differences undoubtedly account for some of 

 these named species. The gradations occurring within P. spinulosum, 

 as it is known to us, bridge all gaps too completely to leave much hope for 

 separation upon the bases of either cultural or morphological differences. 

 Species reported in the literature that are believed to belong with P, 

 spinulosum Thom include the following: 



Penicillium {Citromyces) brunneo-viride v. Szilvinyi (Zentbl. f. Bakt. etc., (II), 

 103: 145, fig. 4. 1941) was described as a fairly rapidly growing species, from almost 

 velvety to floccose, with drops clear, hyphae smooth-walled, vescicular apices up to 

 5.0/n; sterigmata in simple terminal verticils, 12.5^ by 2.5m, rather divergent; conidia 

 globose to subglobose, about 3.7 to 3.8m, with walls double, dark colored, and slightly 

 roughened. There is nothing in the description to separate this species from P. 

 spinulosum Thom except the heavy-walled conidia. A strain from the Centraal- 

 bureau bearing this name, originally from Professor Janke in Vienna and possibly 

 representing the type, closely approximates P. spinulosum in cultural aspect and 

 details of microscopy, but with sterigmata seldom numbering more than 6 or 7 in the 

 verticil. 



Citromyces bruntzii Sartory, in Compt. Rend. Soc. Biol., Paris 76: 605-606. 1914. 

 Sartory applied this name to an organism found on oranges from the Balearic Islands. 

 The data given identifies it as monoverticillate with conidia globose 3.0 to 3.5m in 

 diameter and sterigmata 9 to 10m long. Production of citric acid from glucose and a 

 rose pigment with absorption bands near violet are reported for colonies too heavy 

 to permit the study of individual conidiophores. The species is known only from 

 the original description; Thom (1930) offered a guess that it might approximate 

 P. spinulosum. 



Citromyces citricus Maz6 and Perrier, C. tarlricus M. and P., C. oxalicus M. and 

 P., and C. lacticus M. and P. were cited by these authors (Ann. Inst. Pasteur 18: 558- 

 559. 1904) in a paper on the production of citric acid by Citromyces. Working at 

 the Pasteur Institute in Paris, they proposed these four names for strains of mono- 

 verticillate Penicillia isolated from organic acid solutions, as follows: C. citricus from 

 a 25 percent solution of citric acid, C. tartricus from a 25 percent solution of tartaric 



