384 FIRST FORMS OF VEGETATION. 
cooked. In Lorraine it is a favourite dish, under 
the name of the Polish mushroom. It is well to 
mention, however, that the genus Boletus contains 
perhaps the most poisonous of all the fungi. The 
Boletus Satanas is so called from its deadly pro- 
perties. It may be known by the underside of 
its cap, and its stem being of a blood-red colour. 
The tubes under the pileus of many of the species 
Fic. 41.—MorcHELLA ESCULENTA. 
Reduced half size. 
change on pressure from yellow to blue; and all 
those species which exhibit this change, or possess 
reddish stems or red tubes, should at once be re- 
_jected. 
Next to the common mushroom, the morel 
(Morchella esculenta, Fig. 41), is everywhere es- 
teemed as a valuable and delightful article of 
food, and as a condiment to heighten the 
flavour of ragouts. It is unfortunately by no 
