CHARACTERS OF THE PHYLA 361 



while others place them in a group apart. Diatoms also are 

 sometimes placed in a distinct group. It must be remem- 

 bered also that most botanists include Hsematococcus and 

 Volvox among Algae (p. 178), and place the Mycetozoa 

 either among Fungi or in a separate group of chlorophyll- 

 less plants (p. 179). 



The MuscinecR are the mosses and liverworts, the former 

 of which were fully described in Lesson XXVIII. 



The Vascular Cryptogams are flowerless plants in which 

 vascular bundles are present. Together with the Phanero- 

 gams they constitute what are known as vascular plants, in 

 contradistinction to the non-vascular Algae, Fungi, and 

 Muscineae, in which no formation of vessels takes place. The 

 group contains three subdivisions. 



The first division of Vascular Cryptogams, the Filicincz, 

 includes the ferns, an account of which has been given in 

 the previous lesson. It will be necessary, however, to devote 

 some attention to an aquatic form, called Salvinia, which 

 differs in certain important particulars from the more familiar 

 members of the group. 



The EquisetacecB include the common horsetails (genus 

 Equisetuni], a brief account of which will be given, as 

 they form an interesting link in their reproductive processes 

 between the ordinary ferns and Salvinia. 



The Lycopodine&i or club-mosses, are the highest of the 

 Cryptogams or flowerless plants. A short description of one 

 of them, the genus Selaginella, will illustrate the most 

 striking peculiarities of the group. 



The Phanerogams, or flowering plants, are so called from 

 the fact that their reproductive organs take the form of 

 specially modified shoots, called cones or flowers. They are 

 sometimes called by the more appropriate name of Sperma- 

 phytes, or seed-plants, from the fact that they, alone among 



