130 The Microscope. 



on Navicula Lyra, looking at the center diatom, and you should see 

 the markings on all at once. If you cannot see the lines on any one 

 of the twelve, you should visit some one and have your eyes tested. 

 — Thomas Christian. 



The Electrical Dischaege of the Malapteonrus Electricus. — 

 Mr. Gotch has experimented with a fish brought from the river 

 Senegal, and he found that the discharge on electrical excitation of 

 the skin is not of a reflex character, but is the result of direct 

 excitation of the electrical organ at the point excited. 



2. That the latency of the organ under these conditions is 

 extremely short. 



3. That the excitatory state is propagated through the organ 

 at a rate of about two and a half metres per second. — Journal 

 Nervous and Mental Diseases. 



A New Micrococcus as the Pathogenic Agent of Infectious 

 Tumors ; its Relations to Pneumonia. — Dr. Manfredi (Gazette Med. 

 de Paris) has recently made some researches in regard to the 

 pathogenic agent of morbillous pneumonia in the case of two persons 

 dead of measles complicated with pnevimonia. No autopsy could be 

 obtained, and the experiments were made with the saliva, the 

 lachrymal secretion, and scrapings from the skin. The following is 

 a resume of the results obtained: 



In the two cases the sputa contained constantly, and inde- 

 pendently of the pneumococcus of Friedliinder, a specific micrococ- 

 cus endowed with very pronounced pathogenic properties, to which 

 he gives the name ^^micrococcus of lymphoma or progressive 

 granuloma,'''' which, when inoculated on animals, gave rise to par- 

 ticular pulmonary lesions analogous to those of pneumonia. From 

 the lack of microscopic examinations and on account of the small 

 number of cases on which the researches were based it is not yet 

 possible to say what part this microbe plays in the pathogenesis of 

 secondary morbillous pneumonia. 



The micrococcus has an ovoid form, is often seen as a diplococ- 

 cus, and measures about 0.5/^. It develops tolerably well in all the 

 common cultivating media, and the growth of the cultures is very 

 rapid when air is freely furnished. On thick gelatin, on which 

 typical cultures are obtained, the colonies are presented as discs, first 

 thin and of a blue tint, then thicker and of a pearl gray color, with 

 excavated borders and almost always a nacred reflex on the surface. 

 The growth and multiplication of this micrococcus causes a very 



