Journal of Applied Microscopy. 



509 



G. Wash in water, 5 to 10 minutes. 



7 Iron alum until details become clear. This may take only a few 

 minutes, but may take an hour. 



8. Wash thoroughly in water, 1 to 4 hours. 



9. Ten per cent, glycerine. — 

 10. Mount and seal. 



Cladophora. — This is found attached to sticks and stones in quiet or running 



Fig. 14. Spirogyra. 



From material fixed in chromo-acetic acid and stained in iron alum haematoxylin. A. Single 



cell showing nucleus, chromatophore, and pyrenoids. B. A nucleus undergoing division. 



C. A resting nucleus. D. Zygospores, each showing two nuclei. 



water. It is easily recognized by its characteristic branching. (Fig. 12.) The 

 nuclei of the coenocytic segments are readily brought out by this method. Alum 

 carmine, and Mayer's haemalum are also good stains for the nuclei. 



Hydrodictyon. — This is popularly known as the " water-net." Nets of all 

 sizes should be selected for study. The segments are coenocytic and the nuclei 

 are hard to differentiate except in the younger segments. The method given for 

 Cladophora yields good results. The habit is beautifully shown in preparations 



