CHLOROPHYCEAE 239 



ing an antheridium under a cover glass. For this it is better to stain in 

 phloxine alone, since any overstaining is easily corrected by exposing 

 the preparation to direct sunlight. 



When the fertihzed egg of Chara germinates, a simple filament is 

 produced, homologous with the protonema of a moss. From this fila- 

 ment, the familiar Chara plant arises as a lateral bud. This stage is 

 easily secured. When the pond dries up, collect the dry Chara plants, 

 with their hundreds of black zygotes. After a month or two, put the 

 black zygotes in a dish of water and the filamentous stage, with its 

 young Chara plants, will soon be abundant. They make effective 

 preparations when mounted whole. 



As slides accumulate, the thoughtful student will feel the need of 

 some kind of classification. Of course, one might arrange alphabeti- 

 cally and there would be no need for thought; but we assume that the 

 student who has made enough slides to need a classification will want 

 one which expresses some idea of relationship, even if the idea may be 

 more or less faulty. The classification indicated in Figure 58 is essen- 

 tially that of Oltmann, and does not differ much from that given in 

 Engler and Prantl's Die natiirlichen Pflanzenfamilien. If the student 

 would compile similar diagrams in all the groups, his slides would 

 mean, not only proficiency in technique, but an increasing knowledge of 

 the structure, development, and relationship of plants. 



