Louis Agassiz. 



pouch, like that of our Chromides, and not simply a 

 respiratory apparatus for retaining water. In the 

 Amazonian fish a very sensitive network of nerves 

 spreads over this marsupial pouch, the principal 

 stem of which arises from a special nervous ganglion, 

 back of the cerebellum, in the Medulla oblongata. 

 This region of the central nervous system is strangely 

 developed in different families of fishes, and sends 

 out nerves performing very varied functions. From 

 it arise, 'normally, the nerves of movement and sen- 

 sation about the face ; it also provides the organs 

 of breathing, the upper part of the alimentary canal, 

 the throat and the stomach. In the electric fishes 

 the great nerves entering the electric battery arise 

 from the same cerebral region, and now I have 

 found that the pouch in which the egg of the Acara 

 is incubated and its young nursed for a time, receives 

 its nerves from the same source. This series of facts 

 is truly wonderful, and only shows how far our 

 science is still from an apprehension of the functions 

 of the nervous system." 



The beaches of the Amazon were found to be of 

 great interest, being the resort of many singular 

 creatures. Here were strange turtles, the nests of 

 fishes, alligators, and birds. The Indians were very 

 skilful in discovering the nests of turtles where 

 there was no evidence of their existence upon the 

 surface. They would move quickly along, then 

 suddenly stop and throw up the sand, to invari- 

 ably find the eggs ten or twelve inches below 

 the surface. Here the large alligators lay in the 

 sun and could be easily shot from the canoe, or 



