842 DR. W. R. M‘NAB. 
chronic inftammation of certain parts of the brain, and that 
in the pes pedunculi on one side, where it was most 
advanced, appearances were seen which were identical with 
those artificially produced in the above-mentioned experi- 
ments. In the medulla oblongata of epileptics I have also 
met with lesions which I now feel convinced were due to a 
chronic inflammation of the part, and in locomotor ataxia 
the absence of axis-cylinders, the distended nerve-sheaths, 
and the presence of large numbers of colloid bodies, all tend 
to confirm the hypothesis that we have here also to do with 
a chronic inflammatory affection. 
The Lire-History of Pentcriiium. Translated and abridged 
from Dr. Oscar BREFELD’s ‘ Botanische Untersuchungen 
iiber Schmimelpilze,’ Heft II. By W. R. M‘Nab, M.D. 
Edin.; Professor of Botany, Royal College of Science for 
Treland. (With Plates XVII and XVIII.) 
Amone moulds Penicillium glaucum is the one of most 
frequent occurrence. With unparalleled obtrusiveness the 
little plant forces its troublesome and unwelcome acquaint- 
ance alike on the learned and unlearned. Its pre-eminence 
among moulds depends Jess upon its size than upon its 
abundance, commonness, and highly characteristic pale blue 
colour. The fungus exists everywhere, and it is not, 
possible by any observations to fix the limits of its geo- 
graphical distribution. Its occurrence is dependent on no 
accident; it is the natural and necessary consequence 
of the ubiquitousness of its excessively minute conidia 
(asexually developed spores), which reproduce it with the 
greatest ease. The spores are scattered through the atmo- 
sphere, settling down when the air is still as a constituent of 
the dust; and they are then carried to the ground by rain, &c., 
from whence, on becoming dry, they are again lifted and 
carried by the faintest atmospheric current, if the place 
where they were first deposited was unsuitable for their 
germination. Thus the fungus obtains access everywhere ; 
it is as unavoidable as the air by which it is carried. Out of 
doors it is to be found on all organic substances in a state of 
decomposition, more especially on the larger fungi. In our 
dwellings it is a real plague. Raw and prepared articles of 
food are exposed to its destructive influences, It moulds 
