206 Methods in Plant Histology 



Coprinus micaceus is particularly good for a study of gills, basidia, 

 and the formation of basidiospores, because it is so small that a single 

 section may show a fine series of stages. Gills which are becoming 

 brownish at the tip, but which are still white toward the top of the 

 cap, will show a splendid series of stages. For fixing, cut out pieces 

 of the gills 1 cm. long and 3 mm. thick. Such material fixes well in 

 Flemming's weaker solution. Cut paraffin sections perpendicular 

 to the gills. To show the four basidiospores, sections should be 

 10 to 15 JJL thick; to show details of nuclei, 3 fj, is thick enough 

 (Fig. 59). 



In Hydnum and Polyporus, cut out pieces about three or four 

 spines or three or four pores in width and about 1 cm. long. A 

 rectangular piece which will allow the transverse sections of the spines 

 or pores to be about 4 mm. wide and 1 cm. long cuts better than a 

 piece which will give square sections. 



In Boletus, simply strip off the hymenium and cut into pieces 

 which will give transverse sections of the tubes. 



In Lycoperdon, Bovista, Geaster, and Scleroderma, longitudinal 

 sections of the entire fructification can be cut in paraffin as long as 

 the fresh material is easily sliced with a Gillette blade. 



Young stages of Cyathus, Crucibulum, and Nidularia cut easily 

 in paraffin; somewhat older stages can be cut in celloidin, but 

 mature stages fail to cut by any of our present methods. 



