288 



METHODS IN PLANT HISTOLOGY 



of the refractory objects to the shde, when they wash off if Mayer's 

 albumen fixative has been used. 



There is a general impression that the antheridia and archegonia of 

 Sphagnum are rare and hard to find. Dr. George Bryan, who made an 

 extensive study of Sphagnum suhsecundum, found that antheridia ap- 

 pear in August and archegonia in September. In examining acres of 

 this species, he did not find a sterile plant. 



Fig. 86. — Funaria hygrometrica: A, apex of young sporophyte showing endothecium and amphi- 

 thecium — chromo-acetic acid and Delafield's haematoxylin; 10 m; X420. B, C, and D, transverse 

 sections of a sporophyte of the same age as A, taken at difTerent levels; X255. 



Sporophyte. — It is often difficult to get good mounts of sporophytes. 

 In the younger stages the calyptras are likely to interfere with cutting, 

 while in the older stages the peristome, or hard wall of the capsule, 

 occasions the trouble. If an attempt is made to remove the calyptra 

 in young stages, like A of Figure 86, the apex of the sporophyte usu- 

 ally comes with it. With patience and a dissecting microscope, you 

 may be able to snip off the brown neck of the archegonium which tops 

 the calyptra and makes all the trouble. Land's fixative may hold the 



