THALLOPHYTA 



33 



single cells of the surface. In the Fungi the differentiation into 

 antherozoids, with one doubtful exception, does not take place, 

 and the male organ is only a swoUen cell or branch of a hypha, 

 containing usually undifferentiated protoplasm. In most oases 

 the antherozoids are ciliated and consequently motile ; in certain 

 groups of both Algas and Fungi they are non-motile. In this 

 case they become sooner or later clothed with a cell-wall. 



The female organ is usually an oogonium (fig. 782) consist- 

 ing of a single cell, often carried on a stalk, and containing one 

 or more oosplieres. In other forms it is an archica/rp [fig. 788) 



Pia. 783. 



Fig. 784. 



PUj. 783. Section of thallus of a lichen, sliow- 



ing archicarps, »?,/. -Figr. 784. Procarp of 



one of the Red Seaweeds, tr. Trichogyne. 

 sp. Spermatia. After Kny. 



or proca/rpium [fig. 784) and does not contain any differentiated 

 oosphere. 



The ThaUophyta are divided into three classes, the Algse, 

 Fungi, and Lichens. The first contain chlorophyll, the second 

 do not. As a consequence their habit of life is essentially dif- 

 ferent ; the former can prepare food for themselves from the 

 constituents of the air and the medium in or on which they hve ; 

 the latter are compelled to obtain them directly or indirectly 

 from other organisms. The members of the third class are 

 partly algal and partly fungal. 



