ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 



97 



microscopic organisms (e.g. algae-swarms, Euglense, Volvox colonies, etc.) 

 sensitive to light. The apparatus is shown in fig. 9, where the filter 



Fig. 9. 



Pigs. 10, 11. 



will be observed underneath the stage T. the light parsing through it 

 after reflection at the mirror S. On the stage itself a black cardboard 



Feb. 16th t 1910 H 



