Ken YON, The Brain of the Bee. i^jr 



such as there is with the fibers of other regions, in determining 

 their immediate relationships completely. The bundles of fibers 

 already mentioned as radiating from the place of union of the 

 calyx and stalk as though coming from the latter do so, or 

 rather, to start from the parent cell, pass down into the stalk. 

 At the junction of the stalk and the two roots each fiber divides 

 into two branches one of which passes obliquely downward 

 towards the median line, the other straight forward to the an- 

 terior surface of the brain. Both terminate without further 

 branching, and the inner group form the inner root, and that 

 directed forward the anterior root of the mushroom bodies. 

 Throughout their whole course from the entrance into the stalk 

 to their termination in the inner and the anterior roots the fibers 

 remain parallel, the only deviation from a straight line being 

 a slight waving. They neither decrease nor increase in size 

 but in the stalk they sometimes, though not always, ap- 

 pear to be covered by fine short processes that can neither be 

 described as thread-hke nor tooth-like. These may be arti- 

 facts, but I am inclined to think that their non-appearance 

 might as well be accounted for by defective impregnation. 



There is found, then, in the mushroom bodies a nerve cell 

 with a smooth or irregular body sending a process into the 

 fibrillar substance forming the calyx, branching there profusely 

 aud sending a second process from the first down through the 

 stalk and forming an inner and an outer branch. As will be 

 seen beyond all doubt a little farther on, the branching process 

 in the calyx is the dendrite and the second process is the neu- 

 rite. In the relation of its neurite to other fibers it recalls to 

 some extent the relation between the neurites of the cells of 

 the granular layer and the dendrites of the cells of Purkinje in 

 the mammalian cerebellum, but as a whole the cell seems to be 

 unique among all known nerve cells. 



Fibers Enditig in the Calyx. 



In bichromate of silver preparations, besides the branch- 

 ing dendrites of the cells just described, there may also be seen 

 a large number of other fibers all somewhat coarser than the 



