242 



R. L. KITCHELL 



distances. The anastomoses between fasciculi of the chorda tympani 

 nerves in pigs, cattle, sheep, goats, and horses makes the isolation of 

 functional *' single " fibers more difficult than from the non-fasciculated 

 chorda tympani nerves of dogs and cats. 



CAT. 



Vi-0„; 



HORSE 



Fig. 7. Composite photomicrograph of cross sections of chorda tympani 



nerves from the dog, cat, and horse. See legend Fig. 6 for technique. See 



Fig. 9 for histograms illustrating the fiber diameter frequency distribution of 



these nerves. See also Table 1 (Engebretsen and Kitchell, unpublished). 



The quantity of connective tissue in the chorda tympani nerves was 

 found to be greater in the fasciculated nerves than in the non-fasciculated 

 nerves. The blood vessels within the fasciculated nerves were larger and 

 more numerous than in the non-fasciculated nerves. These anatomical 

 features will be related to technical difficulties in recording neural res- 

 ponses from certain species later in this discussion. 



Table 1. Myelinated fibers in the chorda tympani nerve* 



* Engebretsen and Kitchell, unpublished. 



