92 PRACTICAL BOTANY. 



new plant. The oospore is the sporophyte; the plant 

 itself is the gametophyte. 1 



References for Reading. Goebel's " Classification of Plants," pp. 

 44-46; Bennett and Murray's "Cryptogamic Botany," pp. 222-225, 

 Vines' " Text-Book of Botany," pp. 248, 249 ; Carpenter's " The Micro- 

 scope," p. 502. 



The Coleochaeteae resemble the Red Seaweeds in a num- 

 ber of particulars, and are regarded by some as forming a 

 link between the Green and Red Algae. The color is 

 bright green. They may be found on the leaves and 

 stems of Water Lilies as disks one or two millimeters in 

 diameter. These disks are made up of branching rows of 

 cells radiating from the central part. If plants on which 

 they grow are placed in the light in glass vessels, they 

 often leave their positions and seek the sides of the con- 

 taining vessel. Examined under the microscope, numer- 

 ous hairs are found on the upper surface. 



The asexual reproduction is by the formation of flagel- 

 lated zoospores. Any of the cells may produce these. 

 When the zoospore is ripe, a round opening forms in the 

 cell wall and the zoospore escapes. It then develops by 

 cell division into a new plant. 



The sexual organs are produced in the terminal cells of 

 the branches. The end cells elongate, and the contained 

 protoplasm develops into the female reproductive organ, 

 or carpogonium, which is a specialized form of oogonium. 

 The antherozoids are produced in elongations from neigh- 

 boring cells. (See Fig. 51, og and an.) The fertilization 

 of the carpogonium by the antherozoid has never been ob- 

 served, but there is no doubt that it occurs. A covering 

 or pericarp now grows from the cells just below the fer- 



1 CEdogonium is very common and is unusually good material for a 

 series of Practical Studies. Have on hand fresh gatherings ; also some 

 that is going to decay in a vessel of water. In this way the different 

 forms are almost sure to be found. 



