1892.] MICROSCOPICAL JOURNAL. 43 



together are found marine and tresh-water species of diatoms, several 

 interesting varieties of sponge spicules, very numerous tests or cara- 

 paces of fresh-water rhizopods, and several species of marine forami- 

 nifera. Also there may be seen varieties of pollen grains or spore 

 capsules, and man}- plates of mica. On two slides Mr. Cunningham 

 has shown selected rhizopods, to be viewed strictly by polarized light, 

 and two slides of deposit strewn so as to show the various associated 

 micro-organisms by polarized light. These slides have no cover 

 glasses, but are covered by a thin film of mica, with the object of 

 intensifving the brilliancy of the prismatic eflects. Under this ar- 

 rangement we are provided with a kaleidoscopic effect of color, pro- 

 duced bv the polarized light when the polarizing prism is revolved. 



The diatoms are being washed by Dr. Geo. H. Taylor, of Mobile, 

 without use of acids. He is now engaged on the reduction of a large 

 bucketful of the deposit. The diatoms indicate an aggregation of about 

 fifty marine and fresh-water species — Actitiocychis Ehrenbergii^ 

 Canipylodiscus crebrosiis^ Nitzschia circumsuia, and Terpsinoe 

 miisica. Another interesting feature is that Triceratium favus'\^ ab- 

 solutelv absent, and that Cymatoplciira clliptica and a pretty Acant/ies 

 are seen in evei'v lot of earth. 



The material makes elegant balsam or dry mounts for condensed 

 surface illumination for binocular. It is of unusual interest before acid 

 treatment, as it shows a fair mixture of a wide variety of rhizopods, 

 sponge spicules and diatoms, not to mention a great variety of trans- 

 parent plant tissues of great diversity of cellular structure, with scales 

 of mica, which polarize very prettily. 



BACTERIOLOGY. 



Discovery of the Influenza Bacillus. — Koch is authority for the 

 announcement that this bacillus has been found by Dr. Pfeiffer of the 

 Koch Institute, and independently by Dr. Canon of the Moabit Hospi 

 tal in Berlin. The Berlin correspondent of the London Lancet de- 

 scribes Pfeiffer's work thus : 



" He examined the sputum of influenza patients, first preparing it by 

 staining. A large number of micro-organisms then became visible 

 under the microscope, and it soon appeared that they were mostly of 

 the same kind. This was always the case with the sputum of patients 

 suffering from influenza alone. When the disease was accompanied 

 w^ith other pulmonary disorders, other bacteria were also visible in the 

 sputum. The sputum of a large number of patients suflering from pul- 

 monary and other diseases, but not from influenza, was examined, but 

 no micro-organism possessing the qualities which characterized that 

 found by Pfeiffer in influenza was formed. A reason why this bacillus 

 has so long escaped observation is that it is far smaller than any micro- 

 oj-ganism heretofore known. 



" Dr. Pfeiffer next cultivated the bacillus in pure cultures, and here 

 another explanation of the lateness of its discovery came to light. The 

 colonies were so small that they could easily be overlooked. At first 

 they were visible only under the magnifying glass. Glycerine agar was 

 the best nutritive medium. The most characteristic thing about this 



