172 THE MICROSCOPE. 



The above is given for immersion lenses and varies slightly 

 with dry lenses. 



Ring-worm. — I have rarely spent a more instructive and 

 pleasurable evening with the 'scope than I did a few evenings 

 ago when I was fortunate enough to view five different kinds of 

 lungi. A youQg lady called with a ring- worm on her arm and 

 was tilled with fear of blood disease. With a spatula a little of 

 the "worm*" was scraped off placed in the center of the slide, 

 flooded with potassium hydrate, covered and examined with a 

 quarter inch objective when the characteristic mycelium of 

 Achorion schoelinii appeared. This is pictured on page 52 of 

 "Microbes and Ferments," Vol. LVI, of the International Scien- 

 tific series. The young lady bound the spot with cotton soaked 

 in sulphurous acid and in a few days all traces were removed. 



Grape -mould. — My next specimen was a grape containing 

 felt-like mould. Scraping off a small portion and placing it on 

 a slide with the potassium hydrate, I had the extreme pleas- 

 ure of seeing the beautiful fungus Uncinula sf)iralis, a trouble- 

 some disease of grapes. This is described and elegantly fig- 

 ured in the report of the U. S. Department of Agriculture for 

 1886, page 105, plate 2. It was a sight worth seeing and was 

 obtained by simply scraping some grapes purchased for the 

 table. 



Ragweed. — I then took some leaves of ragweed. They 

 were growing around the sides and under the eaves of a country 

 town-hall. A layman claimed that the paint from the build- 

 ing had washed off and covered the leaves. A Coddington lens 

 showed the little spots or conceptacles dotting the white-washed 

 leaves. I gathered a large supply, but placed them between 

 .the leaves of a book. Arriving home, I examined first with a 

 one inch objective as an opaque object, and then examined 

 them as already described in the August "Microscope" p. 126, 

 under directions for mounting Erysiphe. This fungus was 

 very interesting but I found it almost buried beneath several 

 Greek and Latin names. Dr. M. C. Cooke in his little work on 

 -Microscopic Fungi" figures it in plate XII, figure 249, and calls 

 it Erysiphe linhii. Ellis & Everhardt in their great work on 

 American Pyronomycetes on page 12 call it E. cichoracearum and 

 also mention the synonyms under which it is known. 



