RELATIVES OF THE FERNS 53 



enormous help to the study will be a microscope 

 of even a low power. With its aid it will be 

 seen that some of the spores are really objects 

 of great beauty, whilst the lenses will reveal 

 many points which could not possibly be 

 observed with the unaided vision. 



Another important group of plants which 

 is closely allied to the ferns is the horsetails 

 {Equisetums). Like the club mosses, it is 

 generally believed that the early types of 

 horsetails were on a very large scale, and 

 played a big part in the formation of coal 

 deposits. Many of the fossil remains, which 

 bear a more or less striking resemblance to 

 our horsetails, must have been immense trees, 

 perhaps as tall as anything which is on the 

 earth at the present time. It is singular 

 how these comparatively primitive plants have 

 been beaten by the more advanced types. 

 Nowadays there is only one living genus of 

 horsetails, which numbers scarcely more than 

 thirty species. Nevertheless, our native horse- 

 tails are very distinctive plants, which almost 

 everyone has noticed from his earliest days. 



It may seem a strange thing to say, but if 

 a number of ordinary people went out to hunt 



