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The presence of a network of nerve-fibres has been observed 
in all domestic mammals, with the exception of the pig. 
Professor Pfliiger, of Bonn, has two important papers in 
Schultze’s Archiv, v, Part 2, on the Ending of Nerves in 
the Salivary and Pancreatic Gland. He figures an abrupt 
termination of the nerve tissue amongst a group of gland- 
cells, with the substance of which he believes the nerve to be 
continuous. Hyperosmic acid has been used to bring out 
this relation. Pfliiger calls this method of termination “ Pro- 
toplasmafiisse.” This matter, at which Pfliiger has w'orked 
for some time, and published more than three years since, 
should be examined into by some English microscopists. 
Franz Boll, a student at Bonn, confirms Pfliiger’s views in a 
paper translated in this Journal, vol. vii, p. 262. Professor 
Pfliiger here adds some very interesting observations on the 
development of the epithelium of the gland, tracing its rela- 
tion in origin to the nerve. 
Mcscle. — C. L. Heppner describes in SchultzeVArcAfc, v, 
Part 1, a Peculiar Optical Appearance in Striped Muscular 
Fibre , which is neither more nor less than the dark line 
intervening in the light space between two dark spaces of the 
fibre described long since by Sharpey, and figured in Quain 
and Sharpey’s ‘Anatomy, 7th edit., 1867, vol. i, p. 118. 
Dr. Schwalbe has in Schultze’s Archiv, v, Part 2, a very 
interesting comparative study of the Finer Structure of the 
Muscle Fibres of the Invertebrata, illustrated by two plates. 
The comparative histology of muscular tissue is well rvorth 
prosecuting still further. Some very careful drawings of 
muscle fibres in Echinoderms, Ccelenterata, Annelida, Gepliy- 
rea, and Mollusca are given. 1 
On the Structure of Smooth Muscular Fibre. — G. 
Schwalbe, in Max Schultze’s Archiv, band iv, heft 4, 
gives the results of investigations made into the structure of 
unstriped muscle taken from the dog’s bladder. The fibres, 
after a prolonged action of a weak solution of chromic acid, 
could be readily isolated. The three chief elements of these 
fibres were : one or two nuclei, each containing one or two 
nucleoli ; a small quantity of protoplasm ; and contractile 
substance. This article concludes with some remarks upon 
the shape of unstriped muscular fibres. It may be readily 
observed, on transverse section of involuntary muscle, that 
the uninjured fibre-cells are generally round, or of an irregu- 
lar spindle shape. After isolation, however, fibres are often 
1 The cellular muscular fibres figured in my paper on “ Cheetogaster,” 
herein, and similar fibres in low Crustacea observed by Dr. Van Beneden, 
are wonhy of mention in connection with this subject. — E. It. L. 
