THE AMERICAN 



MONTHLY 



MICROSCOPICAL JOURNAL, 



VOL. XIX. FEBRUARY, 1898. NO. 2. 

 Contents. 



Microscopic Forms in Yellowstone Park. (Illustrated) 17 



Some Photomicrography Experiments 20 



Methods in Microscopical Techniqne 21 



Dahlia as a Stain for Bacteria 23 



Gates' Double Microscope 25 



Practical Suggestions. — Ptlidium ciliare, Bones, Cartilage, Fats.... 26 

 Editorial. — A. M. Society, Moulds, Periodical Sale, Catalogue, Ob- 

 jects, Best Objective, Leprosy, Vaccination, Leuwenhoek 27 



Science-Gossip. — Chlorosis, Carcinoma, Celloidin Embedding, Freez- 

 ing, Diatoms, Laboratory Dish, Forgeries, Paraffin, Cutting Eings, 



Tobacco Seeds, To Split Selenite, Mounting Pollen 29 



Recent Publications. — Clinical Diagnosis, Ball's Bacteriology, Abbott's 



Bacteriology 32 



Microscopic Forms at Yellowstone Park. 



The bacteria of the hot pools. — At the hottest pools 

 maybe found filamentous growth of pearly luster, white 

 or gray scattered along the edges of the little streams or 

 forming a delicate net work at the bottom. These tufts 

 shown in fig. 1, may be six inches long, and the water is 

 never below 85° C (185 F.). 



Beggiatoa. — Figure 2 shows these filaments under low 

 powers, a quite homogeneous strand, stiff, stringy, gelat- 

 inous and coated with minute crystals. Carbon bi-sul- 

 phide dissolves them which proves the deposit to be 

 sulpher. Stain and put under an immersion lens of 1,000 

 diameters. Then innumerable rod-like forms of bacteria 

 appear imbedded in the gelatinous matrix. All these 

 chains vary in length the larger breaking up into the 



