HARDWICKE'S SCIENCE-GOSSIP. 



157 



brings out"! all their different structures in a most 

 satisfactory manner. In order to examine the various 

 tissues in recent plants under the microscope, the 

 student finds it most advantageous to have his 

 specimens double stained, but the fossil botanist 

 finds this done for him, the process having been 

 undergone in the laboratory of nature untold ages 

 ere man himself came into existence. So that the 



even other colours, are found in the various plant 

 structures. Generally speaking, the walls of the 

 vessels and cells of the plants are of some shade of 

 brown, while the interiors of the vessels and cells 

 and intercellular spaces are filled with calc-spar or 

 pure carbonate of lime, which though frequently a 

 pure white, is generally slightly stained. 

 Zygosporitcs longipcs. — This is an 



egg-shaped 



Fig. 101.— Zygosporites longipes. 



Fig. 99. — Sporocar/ou cellulosum. 



Fig. 1 00. — Zygosporitcs brevipes. 



so-called new process of double staining is another 

 illustration of the old saying, "There is nothing new 

 under the sun." The material in which these fossils 

 are best preserved is a light carbonate of lime, which 

 appears to have completely saturated the bed of 

 vegetable matter which has preserved its original 

 colour of deep brown. But while the prevailing 

 colour of the vegetable debris is brown, yet almost 

 an endless variety of shades of brown, and sometimes 



Fig. 102. — Zygosporites oblonga. 



organism and rather larger than Z. brevipes. The body 

 is covered with spines, which are fewer in number, 

 and are also longer than those of Z. brevipes, hence its 

 specific name of longipcs. The spines are seated on 

 somewhat broad bases, and gradually become atten- 

 uated as they approach the tips, but these tips expand 

 into a cup-shaped form, but which appear to be 

 divided into four segments, as seen in their transverse 

 sections. In transverse sections of the spore, six 



