THE PRINCIPLES OF BOTANY. 
289 
of the bone. Mr. Fleming states that the superior surface 
of the navicular bone is never affected. I have one specimen 
before me now in which both surfaces are deeply ulcerated. 
I will take the earliest opportunity of showing it to him, and 
any others I may find on examining my collection. 
The only reason I can assign for the disease affecting the 
under surface of the bone, to the almost entire exclusion of 
the other articulatory surfaces, is, that that face of the bone 
is the first to become affected when its natural healthy 
supply of blood is interfered with. Mr. Fleming also says 
that concussion has little (if anything) to do with the pro- 
duction of navicular disease. I think he will not make many 
converts to that theory. As we become better acquainted 
with the process of congestion, inflammation, healthy nutri- 
tion, and diverted nutrition, we shall then be better able to 
prevent disease. 
THE PRINCIPLES OF BOTANY. 
By Professor James Buckman, F.G.S., F.L.S., &c. &c. 
(Continued from p. 209.) 
Having stated some of the principles connected with 
what we may now term terrestrial fungi, we would direct 
attention to some anomalous forms which seem to be entirely 
aquatic, and we do so to stimulate inquiry into the history of 
an aquatic plant of obscure vegetable origin, but which, 
though little be known about it, is yet admitted on all hands 
to exert a wonderful influence on health, both in man and in 
the inferior animals. 
Most microscopists are aware that in town wells some of 
the brightest looking waters yet contain a semitransparent 
fungoid substance, and there are certain diseases constantly 
occurring where such waters are used as impel the medical 
adviser at once to state that there is something wrong with 
the water. 
In order to trace the history of this fungus the more clearly 
we extract the following remarks by Dr. Edwin Lankester, 
from the Quarterly Journal of Microscopical Science : 
“ In the autumn of 1854 I was requested to examine the 
well waters in the parish of St. James, Westminster, as some 
of them, not without reason, as it subsequently turned out, 
had been suspected of communicating or predisposing those 
