ALGA-LIKE FUNGI 59 



water and are often highly differentiated both as to form and tissues. 

 Some reach hundreds of feet in length as, for example, Macrocystis 

 which grows in the Pacific Ocean off the coast of California. Other 

 forms typical of the group are Ectocarpus, Laminaria, and Fucus. 



Class III. — Rhodophyce^, The Red Alg^ 



A greatly diversified group comprising the majority of marine algae. 

 Their vegetative bodies vary from simple branching filaments through 

 all gradations to forms differentiated into branching stems, holdfasts 

 and leaves. Their color may be red, purple, violet, or reddish 

 brown and is due to the presence of phycoerythrin, a red pigment. 

 Among this group are classed Chondrus, Nemalion, Corallina, etc. 

 Chondrus is the sole official alga in the U. S. P. and belongs to the 

 family Gigartinacese. 



SUBDIVISION IV.— FUNGI 



This great assemblage of thallophytes is characterized by the total 

 absence of chlorophyll and so its members possess no independent 

 power of manufacturing food materials such as starches, sugars, etc., 

 from CO2 and H2O. Consequently they are either parasites, depend- 

 ing for their nourishment upon other living plants or animals, called 

 hosts; or saprophytes, depending upon decaying animal or vegetable 

 matter in solution. Some forms are able to live either as saprophytes 

 or parasites while others are restricted to either the parasitic or sapro- 

 phytic habit. The vegetative body of a fungus is known as a mycelium. 

 It consists of interlacing and branching filaments called hyphae, which 

 ramify through decaying matter or invade the tissues of living organ- 

 isms and derive nourishment therefrom. In the case of parasites, the 

 absorbing connections which are more or less specialized and definite 

 are called haustoria. In the higher forms the hyphae become consoli- 

 dated into false tissues, and assume definite shapes according to the 

 species. Of this character are the fructifying organs which constitute 

 the above ground parts of Puff Balls, Cup Fungi, Mushrooms, etc. 



Class I. — Phycomycetes, or Alga-like Fungi 



The Phycomycetes represent a small group of fungi showing close 

 affinity with the green algae. Their mycelium is composed of coenocytic 



