34O LOUIS M. HICKERNELL. 



DESCRIPTION OF PLATE I. 



FIG. i. Cross section through the mid-body region of a normal expanded 

 Philodina roseola. Leitz compensating ocular 4, obj. 2mm. 



Fig. 2. Section of a rotifer kept for eighteen days previous to fixation in an 

 evacuated calcium chloride desiccator. Leitz oc. 4, obj. 2mm. 



FIG. 3. Section through a normal animal, not expanded. Leitz oc. 4, obj. 2mm. 



FIG. 4. Section through the vitellarium of a normal animal. Leitz oc. 12, obj. 

 2mm. 



FIG. 5. Section of the vitellarium of an animal dried in an evacuated desiccator 

 for fourteen days previous to fixation. Leitz oc. 8, obj. 2mm. 



FIG. 6. Longitudinal section of an animal recovering from desiccation. The 

 rotifer was kept in an evacuated desiccator for fifteen days, then placed in water 

 for an hour and fifteen minutes, at the end of which time it was fixed. Leitz oc. 8, 

 obj. 2mm. 



FIG. 7. 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 fixed. Leitz oc. 8, obj. 2mm. 



