The Lower Plants 73 



that there is no trace of the chromatophores that give 

 the green color to most plants. The fungi are there- 

 fore unable to perform photosynthesis, and so far as 

 we know, must obtain their carbon from the organ- 

 ized carbon compounds of other plants or animals. 



Origin of Fungi. It is generally assumed that 

 the fungi are descended from plants containing 

 chlorophyll, although this is not universally ad- 

 mitted, and it is conceivable that the true fungi rep- 

 resent a series of forms which have never possessed 

 chlorophyll. A comparatively small .number of 

 fungi, usually associated under the name of Alga- 

 fungi, show a more or less evident resemblance to 

 certain algae, and some of them at least may very 

 safely be considered to be of algal origin. It is an 

 open question, however, whether these alga-fungi 

 are really related at all to the true fungi, or, indeed, 

 whether they all are related among themselves. 

 There is some reason to suppose that some at least 

 of the true fungi are really derived from these alga- 

 fungi ; but this point is by no means certain. 



Among the most alga-like of the fungi are the 

 water molds (Fig. 6), whose resemblance to cer- 

 tain algae, both in structure of the plant and its 

 reproduction, is sufficiently close to make probable 

 a real relationship between the forms. The water 

 molds are found growing upon the bodies of 

 dead insects or other animals in the water, and 

 sometimes are parasitic, attacking young fish or 

 older ones that have been wounded. The slender, 



