ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 



115 



for the whole apparatus. In each chamber one thermometer takes the 

 temperature of the air, while the bulb of another is imbedded in felting 

 so as to give the temperature of the walls. 



(4) Photomicrography. 



Israel and Stenglein's Photomicrographic Microscope.* — Dr. O. 

 Israel's photomicrographic apparatus (fig. 19) may be used either in a 



Fig. 19. 



Fro. 20. 



* Stenglein, M., and Schultz-Hcncke, ' Anleitung zur Ausfiihrung mikrophoto- 

 graphischer Arbeiten,' 8vo, Berlin, 1887, pp. 4-12 (2 rigs.), 14-6 (1 fig.). 



I 2 



