io6 
HYMENOMYCETES 
B. luridus (from the lurid colours), “ Lurid Bolet.” 
Plate XXXIV. i. 
P. 3-6 in., olivaceous, brick-red, dingy-brown, etc., minutely 
tomentose. F. very thick, firm, yellow, instantly changing 
to indigo-blue when cut. T. up to in. long, almost free, 
greenish olive, openings minute, roundish, vermillion, orange, 
or brown. 5 . 2-5 in., very stout, usually bulbous below, red¬ 
dish or yellow with red blotches, sometimes vaguely reticu¬ 
lated with crimson-red. In woods, under trees in pastures, 
and in hedgerows in ant. Very common and very poisonous. 
Concerning the curious bluing of the flesh in this and 
other species, Massee writes: “ The peculiar property 
possessed by the flesh of some species in becoming a more 
or less intense blue when cut or broken depends on the 
presence of two distinct substances in the flesh—one, a 
resinous substance that becomes blue when brought in 
contact with ozone; the other, a substance soluble in 
water, which ozonises the oxygen of the air, and then effects 
a combination with the resin, to which it gives up its oxygen 
in the form of ozone, the result being a more or less intense 
blue coloration.” The resinous substance is guaiacum; 
the oxidising ferment is known as tyrosinase. The phe¬ 
nomenon is not confined to the Boleti, but is possessed by 
other fungi in the various groups. 
B. scaber ( scaber , rough — in allusion to the stem), 
“ Porcinello.” Plate XXXIV. 3. 
P. 3-6 in., viscid when moist, white, cinereous, olive-brown, 
etc. F. thick in the centre, white, unchangeable. T. f in., 
long, almost free, openings irregular, subangular, white at 
first, then dingy-brown. S. 5-7 in., conical upwards, pale, 
rough, with black or orange scales; sometimes coarsely lined. 
Common in woods in late sum. and aut. Often gregarious. 
Esculent; the Porcinello or Albarello of Italian markets. 
B. versipellis (verto, to turn; pellis , the skin—from the 
changeable colours of the pellicle) somewhat resembles the 
