THALLOPHYTA 



211 



ways (Fig. 591), as to both their minute and conspicuous structures. 

 In the higher forms, such as the mushrooms, this body consists of a stem 

 bearing a cap or Pileus (Fig. 590, a), which bears the spores under- 

 neath, on gills, teeth, or some 

 similar support (Fig. 591). 



The Algae.—The Algae 

 are almost without repre- 

 sentation in the materia 

 medica, although they yield 

 important food supplies, 

 especially in Japan. Even 

 Chondrus, the most impor- 

 tant member in drug com- 

 merce, is in reality only a 

 food, while Fucus acts rather 

 by inorganics, absorbed by 

 it from the sea-water, than 

 by any organic principle of 

 its own. 



Fig. 590. Amanita phalloides. 



Fig. 591. Showing parts of Mushroom — Agaricus 

 {PsalUoia) campcslris: .-1, a section across a number ol 

 gills, h; the liymcnophore, /; the lamellae or gills, one of 

 which is more highly magnified in B, t, the central hyphal 

 tissue; hy, the /)f/7»f?iium, or spore-bearing surface: C, tv 

 portion of gill still more highl>' magnified, (; the hyphae, 

 q; the basidia upon which the conidia or spores are borne, 

 ;■, i'', s" — conidia in different stages. (Sachs.) 



The Algae are essentially aquatics, and differ from the Fungi in 

 possessing chlorophyll or some similar substance, by which they are 

 enabled to build up their food supplies from inorganic matter. 



The last mentioned plant is among the highest of this class. The 

 thallus, or plant body (Fig. 592), consisting of a loose aggregation of 

 single cells, has a well-developed foot, the di.'-k, by which it clings to 



