'ISinS'riS'] Jottings from the Note-hook, &e. 99 
force ; and if the workmansliip has been correct — viz. all the cells 
turned true from one chucking, and the concaves of equal thickness 
and concentric with their respective convex lenses, no errors of 
centering can occur. The usual way of correcting this is by tilting 
the lenses in the cells, in which they are cemented with Canada 
balsam ; but at the best this is only to some extent substituting 
one error for another. 
YII. — Jottings from the Note-hooJc of a Student of Heterogeny, 
By Metcalfe Johnson, M.E.C.S. 
As the spokes of a wheel converge to the centre, so do the con- 
current radii of evidence point to an axis of truth, either compara- 
tive or absolute. 
The following remarks are simply a description of some experi- 
ments and observations made during the last two years in the 
intervals of leisure in a life of practical medical labour. The 
bearing of the facts upon the great questions of Speciology, 
Epidemiology, and Nature's scavenging, will be at once evident, 
and will (it is believed) be found to run in a similar direction to 
the facts recorded and opinions expressed by Hicks, Sachs, Itsigsohn, 
Fries, Lindsay, Frau Luders, Pasteur, Pouchet, Archer, Lund, and 
others. 
The observations, for the most part, have been made under a 
magnifying power of 250 linear, while a few have required 700. 
In November, 1867, some observations made under 700 linear 
upon the tubules of Lynghya muralis showed every variety (in- 
creasing in size) of Monas lens (or what appeared identical with it), 
to what when outside the tube appeared to be Convallaria in an 
undeveloped state ; green Gonidia, oval green bodies, and masses of 
chlorophyll inside the tubule. 
The various bodies, with the exception of the chlorophyll 
masses, were in active motion ; at the same time, I have frequently 
witnessed masses of chlorophyll slowly traversing the vacuole of 
the tube and, in some instances, the chlorophyll mass has given 
out a blastoderm which assumed a transparent globular form as of 
a vesicle, into which I have seen the small masses of chlorophyll 
empty themselves. In addition to this, bodies apparently identical 
with Monas lens have escaped from the chlorophyll blastoderm 
into the terminal vacuole of the tubule, and there rotated after the 
manner of monas, and in the course of time attached themselves to 
the extremity of the vacuole. This I have witnessed in my re- 
searches to find the bursting gemmules described by Dr. Hicks in 
H 2 
