314 THE MICROSCOPE. 
Every one knows of the old doggerel in which we are told 
that 
“Greater fleas have lesser fleas to bite ’em”’; 
but few of us have any idea of the literal truth of it. Mush- 
rooms, and the lower order of vegetation, of which they are in 
some respects the type, are peculiarly parasitic; but these para- 
sites are found still to have other parasites to worry them. Mr. 
Worthington J. Smith, a well-known English mycologist, has 
recently published a paper, describing a parasite found on the 
common mushroom, and which proves to be a great foe to the 
mushroom cultivator. It attacks the hymeneal surface of the 
gills, having the same color, and is entirely invisible to the naked 
eye. Small gelatinous spots may, however, be detected by a 
strong pocket lens; and their presence may even render, Mr. 
Smith says, the common mushroom poisonous. He names the 
parasite Saprolegnia mucophaga. Another parasite, or an ally of 
the mushroom, Agaricus gloiocephalus, he describes as Fustsporvum 
mucophytum. This also is the exact color of the gills; and Mr. 
Smith has a rap at what some “ young botanists would call the 
protective resemblance,” and the “mimicry” involved in the 
fact. Besides these, there is yet on the common mushroom often 
a parasite on the gills in the shave of a thick, white mold, and 
that weaves a thick, floccose web of mycelium all over them. 
The under surface of the mushroom, instead of the pretty brown 
salmon-color of its normal condition, looks like one woven mass 
of felt. He has not yet been able to develop the full character 
of this species so as to warrant him in describing and naming 
it—. The Independent. 
MICROSC ORM: 
To srupy THE RoTIFERS.—Dr. C. T. Hudson, the President of 
the Royal Microscopical Society, remarks that for the correct 
observation of the Rotifera there are only two directions to be 
given: first, see them alive; second, for reagents use patience. 
Mr. J. D. Hardy, at the same meeting of the Society stated that 
he had found that the best way to keep the rotifers quiet for a 
sufficiently long time to be able to draw them, especially when 
they were very active creatures, was to make a strong solution 
of common loaf sugar, and add it drop by drop to the water 
