PH7C0PHYTA. 



137 



Plantains, Mints, and some leguminous plants. In the study of these 

 minute plants consult vol. i., part iv. of Rabenhorst's Kryptogamen- 

 Flora, 1892. 



Systematio Literature. — WoUe, Freshwater Algse of the tJnited 

 States, 156-204. Saccardo, Sylloge Fungorum, 7'. Flora of Ne- 

 braska, 1, 29-35. pi. i. 



APPENDIX TO PROTOCOCCOIDE^. 



The two organisms described below are usually regarded as plants, 

 but they have little in common with plants aside from their green 

 color. In all probability they, with a few near relatives, must event- 

 ually be placed outside the limits of the Vegetable Kingdom. 



A. Fandorina is the pretty name given to a common fresh-water 

 organism. It consists of a globular colony of green cells ; each cell 

 is provided with two cilia, which project outward from the ball, and 

 by rapid vibration give it a rotary motion (Fig. 67). At a. certain 

 stage of its development some of the cells of the colony escape and 

 swim about in the water ; finally two come in contact with one an- 

 other and unite, forming a resting spore {E, F, G, H, Fig. 67). 



Fig. 67.— .4., a colony of Pandorina monim ; C, sexual cells escaping ; E, 

 F, G, union of sexual cells ; H, resting spore. All highly magnlfled. 



After a period of rest, the resting spore bursts its wall, the proto- 

 plasm escapes, and swims about for a time by means of two cilia with 

 which it is provided ; at last it comes to rest and divides itself into 

 sixteen cells, which then constitute a new colony similar to that with 

 which we started {A, Fig. 67). 



B. Volvox. — The little spherical Volvox (Fig. 68) of the pools and 



