•> ,;> Bulletin 167 



marked with curved lines. The internal structure became 

 grumose, to broken and fimbriate. A slow and somewhat delayed 

 liquefaction began as a finely granular outer zone, the appear- 

 ance thereafter conforming to the type, CXLVIII. 



Ps. alba is described as the type of the non-liquefying and 

 tardy liquefying group. Microscopically ; punctiform, raised, 

 smooth, yellowish. Microscopically: roundish, entire to broken. 

 yellow-brown, somewhat gray towards the edge. Internally 

 grumose to fluccose. Ps. putrida; slower growth than Ps. alba: 

 macroscopically like the latter. Microscopically; round, entire, 

 brownish, granular. The surface was slightly ridged and fur- 

 rowed giving a shadowy appearance to the colony. Later the 

 colonies became grumose to broken and were dark brown in color 

 Ps. tenuis. — Macroscopically; like Ps. alba. Microscopic- 

 ally; roundish, granular to grumose or floccose, becoming spiny 

 or fimbriate. 



Strain CXL. — Macroscopically; like Ps. alba. Microscopic- 

 ally; much like the type, being round, convex, entire, yellowish- 

 brown, and granular toward the center, the edge being thicker 

 and somewhat grayish. Others were yellow-brown throughout: 

 larger ones were often roundish with undulate edge. Young 

 colonies were perfectly round, finely granular, brownish discs, 

 with sharply defined edge. 



Strain LI. — Macroscopically ; like Ps. alba. Microsa >pically : 

 round, entire, yellow-brown, finely granular, concentrically banded 

 or zoned. The edge was comparativclv thin. 



Ps. longa, and Ps. mesenterica. — Macroscopically; like Ps. 

 alba. Microscopically; round, brownish discs, somewhat zoned: 

 internally granular becoming nucleated at the center; the per- 

 iphery was thinner, coarsely granular, and zoned with granular 

 edge. A thin bordering zone showed coiled or curled surface 

 markings. The colonies of the two strains at first were alike, 

 but in 4 days slow liquefaction began in those of Ps. mesenterica. 

 10. Agar colonics. — Ps. alba. Growth rapid. Colonies 

 were at first round to irregular, smooth, edge thin and entire. 



