PESTS AND DISEASES. 49 



would have to be used. For all ordinary purposes shelves 

 of stout wood will suffice. 



The house should be heated with a flow and return Sin. 

 pipe running around the pathway, the piping being attached 

 to a boiler. A house of this kind is useful for forcing 

 rhubarb and seakale on the floor shelves, and its construc- 

 tion need not be a costly affair. We give herewith a section 

 of such a house. AA shows the beds or shelves, and B the 

 pathway. AVliere there is no wall available to build a 

 lean-to, then build a span-roof with side walls 6ft. high, 

 under the shade of trees, or where the sun does not shine too 

 powerfullj- upon the structure in summer. The dotted lines 

 show the slope of the beds when prepared and spawned. 



CHAPTER XII. 



PESTS AND DISEASES. 



Mushroom Pest (Sciara ingenua). — These active little 

 ins-ects often infest mushroom beds, and do considerable 

 injury to the crop. 



Remedies. — Spray the walls, soil, and floor before spawn- 

 ing with 21 per cent, of lysol ; or dissolve two ounces of 

 salt in a gallon of tepid water, and sprinkle the beds after 

 .^oiling with this. 



Mushroom Disease. — Mushrooms are sometimes 

 attacked in an early period of tlieir growth by a minute 

 parasitic fungus (Hypomyces perniciosus), the mycelium of 

 which develops in the Mushroom and causes the stem to 

 assume a swollen, bulbous-like mass of growth. The infected 

 mushroom consequenth- fails to grow properly, and the stem 



E 



