210 GENERAL CHARACTERS OF CRYPTOGAMS 



PRINCIPAL GROUPS OF CRYPTOGAMS 



The main groups of the cryptogams are indicated in the following 

 table : 



1. Thallophyta or Thallophytes. 



(a) Fungi. 

 (6) Algae, 

 (c) Lichenes or Lichens. 



2. Bryophyta or Bryophytes. 



(a) Hepaticae or Liverworts. 

 (6) Musci or Mosses. 



3. Pteridophyta or Pteridophytes. 



(a) Equisetaceae or Horse-tails. 



(b) Lycopodiaceae or Club-mosses. 



(c) Filices or Ferns. 



Each of these groups will be briefly considered, in so far as relates 

 to its contributions to the materia medica. 



Thallophyta. — The Fungi. — The Fungi comprise plants destitute of 

 true chlorophyll, and therefore incapable of building up their own 

 food from elementary substances. Their structural and physiological 

 characters are exceedingly varied. 



To the Fungi belong the Bacteria, contributing the great majority 

 of disease germs, in the special uses of which we are yet to find the 

 most important part of our materia medica. The study of this group 

 pertains to the subject of Bacteriology. 



To the Fungi belong also the yeast plants, valuable medicinal agents, 

 but unicellular, and to be studied only in the microscopical laboratory. 



Among the drugs of interest to commercial pharmacognosy, occur 

 only Kefir grains, Taka-diastase, Ergot, and the Agarics, all of which 

 belong in the higher divisions of the group. 



The vegetative portion of the Fungi consists of a tissue called 

 Micelium, formed of filaments, often growing into large and dense 

 masses. In many, this micehum, after forming into a hard mass, 

 becomes dormant, and constitutes a resting body called the Sclerotium 

 (e. g., Ergot), which later, under suitable conditions, gives origin to the 

 spore-bearing body. Some of the Fungi have no higher mode of repro- 

 duction than that of simple division (fission), although almost all of 

 them reproduce by means of spores. These spores are borne in various 



