1863.] 571 



decomposed, oil-globules being gradually set free. Near the fundus 

 or rounded end is seen the very large circular nucleus with its 

 nucleolus. In some of these cells, at about the central part or a 

 little higher, are a number of oval nuclei, some of which are in con- 

 nexion with fibres. The matter of which the mass of the cell con- 

 sists gradually diminishes in diameter, and contracts so as to form 

 a fibre, in which a nucleus is often seen. At the circumference of 

 the cell, about its middle, the material seems gradually to assume the 

 form of fibres, which contain numerous nuclei, and these pass around 



So-called " unipolar " nerve-cell, with, 1st, a straight, and 2nd, a spiral 

 fibre emanating from it. The fibres continuous with these are seen to 

 pursue opposite directions. Magnified 700 linear. 



I .... I ... i I 1000th of an inch X 700. 

 10006' 



the first fibre in a spiral manner. Thus in the fully formed cell a 

 fibre comes from the centre of the cell (straight fibre), and one or 

 more fibres (spiral fibres} proceed from its surface. These points 

 are represented in the figure*. 



2. On the formation of ganglion-cells in the fully formed frog . 



This subject is arranged under the three following heads, but as it 

 would not be intelligible without figures, it will not be given in 

 abstract. The development of these cells and many other structures 

 may be studied in the fully formed animal as well as in the embryo. 



a. Ganglion-cells developed from a nucleated granular mass like 

 that which forms the early condition of all tissues. 



b. Ganglion-cells formed by the division or splitting up of a 

 mass like a single ganglion-cell. 



* The specimen from which this drawing was taken has been seen by many 

 observers. 



