January 22, 1897.] 



SCIENCE. 



133 



fishes, amphibians, reptiles, birds and mam- 

 mals were studied by means of methylene 

 blue and alum carmine as in the subsequent 

 paper. The cells of the sympathetic sys- 

 tem are multipolar, except in the amphi- 

 bians, where large unipolar cells are found. 

 The multipolar neurons have several pi"o- 

 toplasmic branches (dendrites) and one 

 axis cylinder (neuraxis); the unipolar cells 

 have the neuraxis only. The cell body of 

 the neurons is enclosed within a nucleated 

 capsule. The dendrites break up into a 

 system of finer branches which terminate 

 between the ganglion cells ; the plexus is 

 extracapsular. Large medullated fibres 

 and sympathetic fibres end in the ganglion. 

 The large medullated fibres branch re- 

 peatedly in the ganglion, ultimately termi- 

 minating in pericellular end-baskets, which 

 enclose the bodies of the sj'mpathetic cells. 

 These end-baskets are always intracapsu- 

 lar, and show different degrees of complex- 

 ity in the various classes of vertebrates. In 

 fishes they may be either very simple, com- 

 posed only of a few fibrillse, or very complex; 

 in the latter case some of the fibrils of the 

 end-basket enclose the cell body of the neuron 

 in question, while others seem to end be- 

 tween small cells, the nature of which has 

 not yet been determined, but which are also 

 within the capsule of the cell. In am- 

 phibians the medullated fibres are twisted 

 spirally about the axis cylinders of the uni- 

 polar cells here found, before terminating 

 in the end-baskets enclosing the bodies of 

 the cells. In reptiles tbe appearances vary 

 greatly in different ganglia and in different 

 parts of the same ganglion. Here, also, 

 very simple end-baskets may be found ; 

 again the medullated fibre may make one, 

 two, three or four turns around the axis 

 cylinder of a sympathetic cell before break- 

 ing up into the finer branches of its end- 

 basket, and finally very complicated end- 

 ings may be observed, where one or several 

 medullated fibres are wound separately 



around the axis cylinder and the adjacent 

 portion of a sympathetic neuron before ter- 

 minating in a very complex intracapsular 

 end-basket. In birds and mammals the 

 medullated fibres terminate in end-baskets 

 which, as a rule, are rather simple, being 

 composed of terminal fibrillar, more or less 

 loosely interwoven and always found be- 

 tween the body of a sympathetic ganglion 

 cell and its capsule. 



Sympathetic nerves ending in a ganglion 

 break up into fine branches, which would 

 seem to terminate in free endings on tbe 

 protoplasmic branches of the sympathetic 

 cells of the ganglion without forming end- 

 baskets. 



This conclusion bas been drawn : The 

 large medullated fibres ending in pericellular 

 baskets come from the cerebro-spinal sys- 

 tem and place the sympathetic ganglia in 

 connection with the brain and cord, whUe 

 the sympathetic fibres with free endings 

 come from other sympathetic ganglia. 



Remarks on the ending of nerves in rmisele 

 tissue, with demonstrations. G. C Huber. 

 The methods used in preparing the sec- 

 tions was the following: A 2 per cent, 

 solution of methylene blue in normal salt 

 solution was injected into a vein. Some 

 time after the injection the tissues were ex- 

 posed and developed in the air. As soon as th e 

 motor endings were recognized in the fresh 

 muscle, the tissues were fixed in ammonium 

 molybdate (Bethe) , dehydrated in alcohol, 

 embedded in paraffine, and sectioned. The 

 sections were then fixed to a slide, stained 

 in alum carmine and mounted in balsam. 

 In order to determine witb some degree of 

 certainty the relation of the end-organs to 

 the muscle fibres, the latter were cut in 

 both horizontal and cross-sections. The 

 conclusions are as follows : 



A. Voluntary muscle (rabbit). The 

 granular sole is an accumulation of sarco- 

 plasma at the point of entrance of the nerve ; 



