172 Bulletin 227. 



present. These spores germinate by producing a very delicate white 

 thread which branches to form a mat of fiber-Hke substance. Many 

 of these httle threads imite into a cord or string which is also white and 

 is shown very well in Fig. 151. This j&ber-like substance is known as 

 the mycelium, though mushroom growers, often speak of it as the 

 "fiber." It can readily be seen in all good spawn. In practical 

 mushroom culture, the spores of the plant, though they serve as seeds, 

 are not used for planting since the use of mycelium or fiber is a far 

 better means of propagating the mushroom. 



After the pieces of brick are planted in the bed, the moisture is 

 absorbed which gives the mycelium the water which it needs for 

 growth. The heat from the fermented manure supplies the necessary 

 temperature, and growth of the fiber soon begins. It spreads out 

 into the material of the bed and also grows upward into the soil with 

 which the bed is cased. In the soil and in the manure of the bed, 

 it forms a large mat of these fibers or mycelium cords. Finally when 

 a sufficient mass of the mycelium has formed the mushrooms begin 

 to develop. The mushrooms are formed by the growth of a large 

 number of the same delicate threads, but a larger number of them 

 grow together and they grow upright. First is formed a minute 

 rounded body the size of a mustard seed. This becomes larger until 

 it reaches the button stage of the mushroom, shown in Fig. 151. 

 This same figure shows a very young stage of the buttons when they 

 appear as minute rounded bodies on the cords. Sometimes the spawn 

 \^dll grow very profusely above the piece of brick which has been 

 planted and appears on the surface of the soil. When this is the 

 case, large numbers of minute buttons make their appearance and 

 form very beautiful objects. All of these, however, do not make 

 mature mushrooms, since there is not food enough for all. Those 

 which get the start grow to maturity, while the smaller ones die. 

 As the button stage is reached, the upper part expands into the cap. 

 The stem is shown as a short cylinder. The gills are formed within 

 the upper part of the button and are first covered by the outside 

 mass, which stretches as the cap expands to form the veil. Finally 

 this veil breaks, exposing the gills on the underside, and hangs down 

 on the upper part of the stem as the collar or annulus. 



Picking the Mushrooms. 



The mushrooms are ready to pick about the time the veil breaks. 

 At this time the gills are a bright pink color. As the plant gets older, 

 the cap expands more and the gills gradually become dark brown 



