150 



The Microscope. 



5th. Other smaller unipolar cells are seen which have 

 pointed extremities, fig. 2, 0. 



6th. The nerve-fibres are found in great abundance passing 

 from ganglion to ganglion, forming a network ; the larger fibres 

 in most instances coursing along the vessels and fibrous trabec- 

 ule, and by following up the smaller fibres, there will be 

 found in the course of some nerves, small fusiform cells, having 

 distinct nuclei, fig. 3, A. 



Fig. 3. 



7th. In the bronchi and alveoli, but more frequently in the 

 alveoli, are minute terminal bulbs or extremities which are 

 more or less pear-shaped, and distinctly nucleated ; the nucleus 

 always in the same relative position, fig. 3, B, and of the same 

 color as the nerve, the protoplasm or material outside the 

 nucleus is not always so colored, appearing very often much 

 lighter ; and in a great many cases, owing, as I believe, to a 

 similarity in refractive index with surrounding tissues, the pro- 

 toplasm or material which immediately envelopes the nucleus 

 is invisible, when the termination appears as represented in fig. 

 3, C. I have a few times seen the nerve-fibres in distinct con- 

 nection and continuous with the nucleus of an end-organ, the 

 substance surrounding the nucleus being also visible, fig. 3, D. 



As to whether some of the larger unipolar cells should 

 also be regarded as nerve terminations I do not know, certain 

 it is, that considering their situation, it seems as though some 



