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The Brain * 



The most striking feature which we recognize in surveying the 

 brain of fishes is its extremely small size, not merely in reference to 



* The brain of fishes has been studied and described with a little more attention 

 to detail than their muscles, and in modern times the distribution of the nerves has 

 been investigated with care. 



In 1685, Collins gave some figures of a certain number of fishes ; the designs 

 were of very moderate merit, and the explanations were all shallow, and not very 

 consistent either. PI. 60 is a squalus, pi. 61 a white ray ; in pi. 63 another ray, 

 the thornback, and an angel fish ; pi. 63 a cod, a lamprey, a trout, and an ombre ; 

 pi. 64 a carp ; pi. 65 a barbel, a plaice, a dab, a flounder, a sole and turbot; pi. 66 

 a flounder, a perch, a gudgeon, and an eel ; pi. 67 a dory, a smelt, a herring, a fish 

 called a gurnet, but which I do not believe to be a real one ; pi. 68 an orphie, sal- 

 mon, mullet, and a mackarel ; pi. 69 a pike, tench, and perch. His pi. 70 repre- 

 sents the commencement of the spinal cord of a mullet, a gurnard, a carp, a pike, 

 and gudgeon. 



In 1761 Camper in his Memoir on the Scaly Ear of Fishes, printed, in 1762, 

 amongst the memoirs of the Society of Harlem, gave a description and figure of the 

 brain of the cod, and in 1762 in a Memoir on the Ear of Fishes in general, printed 

 in 1774, in vol. vi. of those of learned foreigners of the Academy of Sciences, he 

 described and represented those of lophius and of the ray. He was the first who 

 determined its parts, and he gave the name of hemispheres to the hollow lobes placed 

 before tlie cerebellum, and tubercula quadrigemina to the little eminences which 

 they enclose ; the inferior lobes appeared to him to be the corpora albicantia. 



In 1766 Haller, at the end of vol. iv. of his Physiology, gave a description of the 

 brain of the carp, and the same year he sent to the Harlem Academy a memoir on 

 the brain of birds and fishes, inserted in 1 7 88, in vol. iii. of his Opera Minora, p. 191. 

 In this work he describes those of the carp, a cyprinus, a tench, a fera, of a trout 

 from the lake of Geneva, and from that of the Alps, of the grayling, the pei-ch and 

 ling. His descriptions are very detailed, but it is exceedingly difficult to comprehend 

 them, in consequence of the singular way in which he has applied names to various 

 parts ; and also because thei-e are no figures. He calls the anterior lobes, anterior 

 olfactory tubercles ; those beneath inferior olfactory turbercles ; the hollow lobes 

 before the cerebellum, optic thalami ; still he gives the name cornua ammonii to the 

 large tubercles of their interior, and at the very time that he acknowledges that the 

 cerebellum is analogous to that in quadrupeds, he calls the lobes next the cerebellum 

 the cannalated bodies, and that of pineal gland to the globule which is between them 

 in the cyprius. These denominations are by no means fortunate, for the author 

 never meant to convey the notion that there was an agreement of parts. 



In 1776 Vicq d'Azyr in his two memoirs on the anatomy of fishes printed amongst 

 those of learned foreigners presented to the Academy, has inserted some observations 

 on the brains of fishes, and represented but very indifi'erently those of the conger, the 

 eel, those of a labrus, of the otter pike, of the plaice, and the turbot. He does not 

 appear to have had very determined ideas on the names of the parts. 



In 1785 Monro in his anatomy of fishes, gave, pi. 34, a very good figure of the 

 brain of the ray, but what he says in his text p. 44, respecting the brain of fishes in 

 general amounts really to nothing. 



Figures of the brain of the pike, the carp, and silurus, the names of the parts being 

 adopted from Camper, appeared in a thesis by M. Ebel, entitled Observations nevro- 

 logicce ex anatome compurafa, published in 1788, and reprinted in 1793 in the Scrip- 

 tores nevrologici /tunores of Ludwig, vol. iii. 



It was on the authority of these different authors that I published in 1 800, in my 

 Lectures on Comparative Anatomy, vol. ii., my description of the brain of fishes. 

 Adopting the example of Camper and Ebel, I have there considered the middle lobes 

 as the true hemispheres, the tubercles which they contain, the quadrigemina and the 

 inferior lobes have appeared to me to be the optic thalami. I have given in vol. v., 

 figures minutely representing the brains of the carp, eel, and moon-fish, I have also 



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