1863.] 573 



occurring during the formation of all nerve-cells, and on the for- 

 mation of spiral fibres/' hut this is not adapted for an abstract. 

 The term "nucleus" is only employed in a general sense. The 

 author believes that the " nucleus," " nucleolus," and centres within 

 the latter (" nucleoluli ") merely represent centres of different ages. 

 He considers that the matter of the nucleus becomes gradually trans- 

 formed into the formed matter around it, and generally, that these 

 bodies are merely centres which arise in pre-existing centres. He 

 maintains that from the outer formed matter connected with the 

 fibres new nerve-cells could not be produced, while he holds that 

 from the nuclei, nucleoli, and contained centres, entirely new and 

 complete cells could be evolved. So he considers that the difference 

 in the properties and powers of the formed matter on the one hand, 

 and the nuclei and nucleoli on the other, depends upon these two 

 kinds of matter having arrived at different stages of existence. That 

 which is formed cannot form new formed matter, nor appropriate 

 nutrient material ; but the living germinal matter of the nucleus can 

 be resolved into formed matter, and it can appropriate inanimate 

 pabulum, and confer upon it the same wonderful (vital) powers which 

 it possesses itself, and which were communicated to it from pre- 

 existing germinal matter. 



7. Of the fibres in the nerve-trunks continuous with the straight 

 and spiral fibres of the ganglion- cells. 



The conclusions upon this important question are as follows : 



1st. That in some instances very fine fibres, not more than the 

 ^ ^th of an English inch in diameter, are alone continuous with 

 both straight and spiral fibres of the ganglion-cell. 



2nd. That a dark-bordered fibre may be traced to the ganglion- 

 cell as the straight fibre, while the spiral fibres are continued on as 

 very fine fibres. 



3rd. That the spiral fibres may be continued onwards as a dark- 

 bordered fibre which may even be wider, at least for some distance, 

 than the fibre continued from the straight fibre. 



4th. That both straight and spiral fibres may be continuous with 

 dark-bordered fibres. 



It is therefore quite certain that the spiral fibre is not connective 

 tissue, although the author considers it probable that many German 



