218 



Methods in Plant Histology 



not likely to hold such sections to the slide. Use Land's fixative. 

 Here, as in case of antheridia, it is better to use fresh material, 

 putting particularly good pieces into 10 per cent glycerin for glycerin 

 jelly mounts. 



For the development of the archegonium, trim away the leaves 

 which usually cover the cluster. Fix in chromo-acetic acid with a 



FIG. 69. Funaria hygrometrica: A, apex of young sporophyte showing endothecium 

 and amphithecium chromo-acetic acid and Delafleld's haematoxylin; 10 /a; X420; 

 B, C, and D, transverse sections of a sporophyte of the same age as A, taken at different 

 levels; X255.. 



little osmic acid and cut 5 to 10 fj, thick. For a study of the ventral 

 canal cell and fertilization, sections should not be thicker than 3 to 5 ju. 

 Sporophyte. It is often difficult to get good mounts of sporo- 

 phytes. 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 Fig. 69, the apex 

 of the sporophyte usually comes with it. While picro-acetic acid 



