EXPLANATIONS AND REFERENCES, 

 PLATE CLII. 



PAGE. 



Fig. 1. VOLVOX GLOBATOR, a coenobkiQi, showing the fine threads con- 



necting the gonidia, . . . 158 



" 2. Enlarged view of the connecting threads, . . . 158 



" 3. An ideal section of the wall of a coenobiura, . . 158 



" 4. Coenobium with three stellate resting spores, . . . 158 



" 5. VOLVOX STELLATUS, Ehrb., a stellate oogonium or resting spore, 158 



"6. An exaggerated ideal of a section of a coenobium, . . 158 



" 7. A complete antheridium under high magnification, . . 158 



Figs. 8, 9. -warming spermatozoids, ...... 158 



Fig. 11-20. EUDORINA STAGNATE, . . . , .160 



u 11. A coenobium of sixteen cells, normal vegetative condition, . 160 



" 12. Cells dividing, 160 



"13. A matured coenobium, nearly ready to scatter the young spheres, 160 



" 14-21. Spheres in different stages of development, . . . 160 



Figs. 22, 23. Spermatozoids, . . . . . .160 



