158 AVERS. [Vol. VI . 



Wright (293, 1884) has described the sense organs of the 

 Catfish (Amiurus) with liistological detail, and he concludes 

 that they are organs for the perception of wave motion. 



FritscJi (93^ 1889) found an astonishing agreement between 

 the structure of the sense organs of the lateral line and those 

 of the ear, and found the hairs of the former of considerable 

 length, but failed to find a cupula, although he thought one 

 probably existed. 



The Sarasin brothers thought to have found three sorts of 

 sense organs which form a graded series of auditory organs 

 from the simplest condition up to the stage represented by the 

 vertebrate ear, on the surface of the body, and in the head of 

 the larval Ichthyophis glittinosiis. They classified them as 



1. Naked Nerve Hillocks. 



2. Accessory Ears or Nebenohren. 



3. The Ear. 



They recall the fact that all the lower forms possessing the 

 lateral line organs lack the cochlea ; but as they lose the lateral 

 line organs, the cochlea grows more and more in size, becoming 

 ultimately the most important section of the ear. 



The " Seitensinnorgane," as described by Krause (1885, 169), 

 have much in common with taste buds, but must be sepa- 

 rated from them for the present. They are dermal nerve end 

 organs composed of elongated epithelial cells, and are found 

 in Amphioxns, Teleosts, and aquatic Urodela and Anuran larvse. 

 Among these forms they occur abundantly. They are placed 

 on the head, follow the course of the rami laterales n. vagus 

 over the trunk, and probably on to the tail. These have re- 

 ceived very numerous significations. Merkel (1880, 295) sep- 

 arates them from taste buds or terminal buds (Endknospen), 

 which likewise occur on the bodies of fishes ; they are, never- 

 theless, tactile organs. I cannot enter here upon the tracing of 

 these organs among the phylogenetically older fish species. 



The simplest of these organs are probably tactile organs, but 

 fishes do not "feel" with their bodies, endeavoring merely to 

 prevent any contact with bodies denser than water. F. E. 

 Schulze designated them organs for the perception of wave 

 motion (Wellensinnesorgane). But waves do not occur in the 

 deep waters, and the resistance of the water is apprehended by 



