Monthly Microscopical 
312 On Certain Cattle Plague Organisms. [™soutnki bee | toro. 
required for such very small cells, so that no after-cleaning is neces- 
sary, with the exception of washing the upper surface of the covering 
glass with a little soda and water. This, it may be remarked, does 
not affect the gum-dammar ring though it would the gum-arabic 
one, nor the balsam in which the diatoms are mounted ; whereas if 
spirit is used to clean off the slide, considerable danger is incurred 
lest the cover be shifted, whatever may be the nature of the cell, 
using as we do very fluid balsam. 
Of course for the selection of the smaller diatoms a higher power 
than is afforded by a simple lens is requisite. Some persons can 
work with the compound microscope though every movement is 
reversed by it; but for those who cannot do so, some kind of erect- 
ing microscope is necessary. Mr. Curteis, of Mr. Baker’s firm, has 
kindly arranged for me such an instrument. It consists of his 
“travelling or sea-side microscope,” to which has been adapted a 
French erecting prism over the eye-piece, whilst above the circular 
glass stage is firmly fixed an oblong wooden one, giving sufficient 
rest for the hands and wrists of the manipulator. I cannot speak 
too highly of its practical use for the purposes I require. When 
thus employed as a dissecting microscope, the stage is in a hori- 
zontal, and the body in a vertical position, with the prism at almost 
a right angle ; and thus the workman sits in a natural, unconstrained 
position, looking straight to his front, and the tedious and unhealthy 
stooping position entailed by the simple dissecting microscope is 
avoided. It is at the same time in its ordinary state, without the 
prism and extra stage, a very handy and useful little instrument for 
the purposes it is intended for. 
In conclusion, I will only remark that though perhaps none of 
us can hope to equal Moller’s beautiful type-slide with which we are 
all so well acquainted, I do trust that the time is not far distant 
when the diatomists of this country will be able, each of them, to 
make type-slides of the prevailing species ef their own localities, 
arranged according to some acknowledged synopsis; for thus alone 
can a sound knowledge of these organisms be obtained, the vast 
number of synonyms be reduced, order replace the present chaotic 
confusion, and the pursuit converted into a regular science. 
IV.—On Certain Cattle Plague Organisms. 
By Boyp Moss, F.R.C.S. 
Puate LXVILI. Lower portion. 
WuILE engaged, as a member of the Ceylon Cattle-Plague Com- 
mission, in searching for the entozoa described by Dr. Lionel Beale 
as existing in the muscles of the animals dead from the disease, I 
discovered the very remarkable bodies which are represented in 
