PLATE 57 



Fig. 1. A transverse section across a lamellar ridge in a. very early stage 

 of development. 448 diameters. 



Fig. 2. A cross-section through a lamellar ridge divided down in the middle 

 to form two small lamellar plates. 448 diameters. 



Fig. 3. Another lamellar ridge in a stage of development similar to that 

 shown in fig. 2. 448 diameters. 



Fig. 4. A lamellar ridge whose halves are split apart deeply into the pileus 

 flesh. 448 diameters. 



[490] 



