546 



Journal of Applied Microscopy. 



mounting, tease out a small portion and still further dissociate the filaments by 

 tapping smartly on the cover. 



Material stained in eosin shows 

 the external structure well, but may 

 not bring out the nuclei. 



Folysiphonia. — For prepara- 

 tions like those shown in the figure, 

 eosin is a very good stain. To get 

 a brilliant coloring, stain for about 

 twenty-four hours, so that the one 

 per cent, acetic acid may be allowed 

 to act for several minutes without 

 making the stain look weak. Wash 

 thoroughly in water. Not the 

 slightest trace of color should be 

 allowed to come out in the glycerine. 



Sections showing the central and 

 peripheral siphons and other gross 

 features are easily cut in celloidin. 

 It is not very difficult to cut paraf- 

 fin sections, but the nuclei are so small and so hard to bring out that such 

 preparations had better be left for the specialist. 



Fig. 23. Folysiphonia fibrillosa. 



From a preparation fixed in chromo-acetic acid, stained in 



eosin, and mounted in glycerine. X 255. A. An anther- 



idium. B. A cystocarp with carpospores. C. Tetrasporic 



branch with tetraspores. 



Bacteria. 



'x:^c 



M V 



0\' 



Fig. 24. Bacteria. X535- 

 A. Bacillus anthracis, from a paraffin 

 section cut from the liver of a mouse. 

 Fixed in chromo-acetic acid, stained 

 in methyl-violet and bismark brown, 

 and mounted in balsam. B. Staphy- 

 lococcus pyogenes aureus. P>om a 

 preparation stained in gentian violet. 

 C. Spirillum sp. From a prepara- 

 tion stained in fuchsin. 



FUNGI. 



SCHIZOMYCETES. 



No attempt will be made to give methods here. The larger 

 coccus, bacillus, and spirillum forms may be 

 brought out by the method already indicated. 

 Fine preparations may be obtained by inocu- 

 lating a mouse with Anthrax or some other 

 form, and then cutting paraffin sections of 

 favorable organs. Gentian-violet with a faint 

 bismark brown for a background makes a good 

 combination. 



Leptothrix may often be obtained by scraping 

 the inside of the cheek. Beggiatoa, a form with 

 oscillating movements like Oscillaria, is often 

 found in foul water. Its presence may be indi- 

 cated by whitish patches on the bottom. 



It is doubtful whether the bacteria possess 

 even a morphological forerunner of the nucleus 

 of higher plants, consequently there need be no 

 disappointment if the larger forms, like some of 

 the Beggiatoas, fail to show a nucleus. 



