Dr Martin Barry on Fire. 399 
ganglion, and the branch connecting it with the labial gan- 
glion ; from the Loligo,—the optic and brachial nerves. In 
all of these, Prof. Owen recognised filaments (fibres) having 
the same remarkable appearance as those which Dr Barry had 
previously shewn to him in muscle. 
On a subsequent occasion, several physiologists being pre- 
sent, one of whom was Prof. Owen, there were seen muscular 
“¢ fibrille’”—not only flat, grooved, and compound, but sepa- 
rated at the end into their single and simply spiral threads,— 
the really ultimate threads of muscle. In this instance chro- 
mic acid was substituted for the re-agent above-mentioned as 
usually employed by Dr B. in these researches; and in ex- 
amining muscle he now finds the chromic acid to be even pre- 
ferable thereto.* 
To find the muscular “ fibrille’’ of a size proper for examin- 
ation, and so loosely held together that they may be separated 
with ease, the heart of a fish or reptile should be employed. 
Dr Barry has used the heart of various fishes, as well as that 
of the turtle, newt, and frog,—and chiefly the frog. 
To find those states of voluntary muscle in which the trans- 
verse strie are produced by the windings of comparatively 
large interlaced spiral filaments (see abstract of the postseript 
to Dr B.’s paper “on Fibre”), he recommends muscle from 
the tail of the very minute tadpole—when this larva is only 4 
or 5 lines in length (as at the present season), or muscle from 
the leg of a boiled lobster, as being very easily obtained. In 
these states of muscle, the interlacing spirals are seen to dip 
inwards towards the centre of the fasciculus, in a manner that 
may be represented by making the fingers of the two hands to 
alternate with one another. 
To find the filament in red blood discs, Dr Barry recom- 
mends the blood of a Batrachian, such as the frog or newt, 
on account of the large size of the discs in these animals, 
The blood should be examined just before its coagulation, as 
well as at various pericds during the formation of the clot. 
Dr B. has usually added one of the above re-agents or nitrate 
of silver. 
re 
* We are indebted to Dr Hannover for bringing into notice the use of 
the chromic acid for such purposes, 
