406 LOUIS MAX HICKERNELL. 



PLATE V. 



FIG. 21. Longitudinal section through ovary-vitellarium of a rotifer dried in 

 an evacuated desiccator for fourteen days previous to time of fixation. Leitz Oc. 

 8, Obj. 2 mm. 



FIG. 22. Cross-section of vitellarium of animal recovering from desiccation. 

 Animal was kept in an evacuated desiccator for six days, then placed in water for 

 one hour at the end of which time it was killed. Leitz Oc. 8, Obj. 2 mm. 



FIG. 23. Longitudinal section of ovary-viteliarium of animal recovering from 

 desiccation. The rotifer was kept in an evacuated desiccator for fifteen days, then 

 placed in water for one hour and fifteen minutes at the end of which time it was 

 fixed. Leitz Oc. 8, Obj. 2 mm. 



FIG. 24. Cross-section of mastax and salivary gland of a normal undried 

 animal. Zeiss Oc. 6, Obj. 2 mm. 



FIG. 25. Section of mastax and salivary gland of an animal dried in an oven 

 at 40 Centigrade for four days. Zeiss Oc. 6, Obj. 2 mm. 



FIG. 26. Section of salivary gland cells from an animal desiccated, kept four 

 hours in water, and then killed. Zeiss Oc. 6, Obj. 2 mm. 



FIG. 27. Cross-section of brain of P. roseola. Normal active animal. Zeiss 

 Oc. 6, Obj. 2 mm. 



FIG. 28. Cross-section of brain of a rotifer kept in an evacuated desiccator 

 for fourteen days previous to time of fixation. Leitz Oc. 8, Obj. 2 mm. 



FIG. 29. Cross-section of brain of P. roseola dried twenty-four hours, put into 

 water for one hour and then killed. Leitz Oc. 8, Obi. 2 mm. 



