THE CENTRAL ACOUSTIC LOBE 



61 



The acoustic tubercles are well developed. The optic lobes are 

 apparently large, but tiiis is due to the tecta optica being widely 

 separated by a large valvula, just as in the barbel. In this fish the 

 pursuit of food is obviously mostly by taste, touch, and smell. 



What conclusions can be drawn from the study of the herring's 

 brain of the functions of the central acoustic lobe ? This problem 



PLATE 11.— Herrmg. 



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Base of cerebellum (high power) showing desussating fibres and round-celled tissue 

 of central acoustic lobe. One acoustic tubercle with lateral line nerve and 

 fibres connecting the lateral and central lobes. The eighth nerve is seen and 

 fibres to it from the central acoustic lobe. 



can be attacked by the method of elimination. The positive facts 

 point to the conclusion that sight is an important fact, as witness 

 the large optic lobes, and that taste and the gustatory organs can 

 take but little part, as shown by the insignificance of the facial lobe. 

 It would be contrary to the general rule that appears in our 

 study of the carp family, if there was not some functional significance 

 in the presence of the large central lobe we have described. The 

 herring, in the first place, possesses a very elaborate organ of hearing 



