CHAP, in 77?^ Study of the Cryptogams 241 



ascertained that the origin of the lateral buds is not endo- 

 genous, as it appears to be. Equisetum appears in Goebel's 

 work on sporangia ; it is interesting to find that it was in 

 connexion with the organs of this genus that he introduced 

 the term archesporium to describe the cell or cells from 

 which the spores are finally developed. The development 

 of the prothallium was investigated by Buchtien in 1887, 

 though ten years earlier Sadebeck had given an account of 

 the embryology. The anatomy of the stem was investigated 

 by Van Tieghem in 1890, and in 1899 a very exhaustive 

 account of the anatomy of the whole sporophyte through- 

 out the genus was contributed by Jeffrey. 



GREEN Q 



