THxVLLOFHYTES ; AUiJE 225 



The great distinction between these two divisions of 

 Thallophytes is that the Algfe contain cl/lorophi/U and tlie 

 Fungi do not. Chlorophyll is the characteristic green color- 

 ing matter found in plants, the word meaning " leaf green." 

 It may be thought that to use this coloring material as the 

 basis of such an important division is somewhat superficial, 

 but it should be known that the presence of chlorophvll gives 

 a joeculiar power — one which affects the whole structure 

 of the nutritive body and the habit of life. The presence 

 of chlorophyll means that the plant can make its own food, 

 can live independent of other plants and animals. Alga3, 

 therefore, are the independent Thallophytes, so far as their 

 food is concerned, for they can manufacture it out of the 

 inorganic materials about them. 



The Fungi, on the other hand, contain no chloropliyll, 

 can not manufacture food from inorganic material, and 

 hence must obtain it already manufactui-ed by plants or 

 animals. In this sense they are dependent upon other or- 

 ganisms, and this dependence has led to great changes in 

 structure and habit of life. 



It is supposed that Fungi have descended from Alga? — 

 that is, that they were once Alga?, which gradually acquired 

 the habit of obtaining food already manufactured, lost their 

 chlorophyll, and became absolutely dependent and more or 

 less modified in structure. Fungi may be regarded, there- 

 fore, as reduced relatives of the Alg:i3, of equal rank so far 

 as birth and structure go, but of very different habits. 



ALG.D 



154. General characters. — As already defined, Algse are 

 Thallophytes which contain chlorophyll, and are therefore 

 able to manufacture food from inorganic material. They 

 are known in general as "seaweeds," although there are 

 fresh-water forms as well as marine. They are exceedingly 

 variable in size, ranging from forms visible only by means 



