150 



(LopJiius piscatorius,) the spinal marrow contracts suddenly 

 behind the third vertebra and disappears completely before the 

 eighth ; beyond this, only a cauda equina can be perceived, 

 forming two bundles, each of which, composed of sixty-four fila- 

 ments, contains the superior and inferior roots of thirty-two pairs 

 of spinal nerves. (Longet, Aiiat. et Phys. du Syst. Nerv. T. L 

 p. 260.) 



Prof. Owen, the most recent writer on the subject, says, " in 

 Lophiiis a long cauda equina partly conceals a short myelon 

 (spinal marrow) which terminates in a point at about the twelfth 

 vertebra ; in other fishes the myelon is very nearly or quite 

 coextensive with the spinal canal, and there is no cauda equina 

 or bundle of nerve roots in the canal." "In typical fishes it 

 (the spinal cord) gradually tapers to a point in Heterocerxal 

 species, but swells again into a small terminal ganglion in most 

 Homocercal species." " In some bony fishes (Trout, Blenny,) 

 this caudal ganglion is not quite terminal, and is less marked 

 than in the Cod and Bream, in which it is of a hard texture, but 

 receives the last pair of spinal nerves. The absence of this 

 ganglion in the Shark shows that it relates not to the strength of 

 the tail, but to its /orm, as depending upon the concentration and 

 coalescence of the terminal vertebrae." (Owen's Lects. on Comp. 

 Anat. vol. ii. p. 122.) 



With the description of neither of these writers does the pre- 

 sent dissection agree. Wagner has fallen into a double error in 

 describing the cord as being " t»er?/ s/ior/," and the vertebral 

 column as being truncated^ neither of which statements are cor- 

 rect. Arsaky's error is the more remarkable, since he took the 

 trouble to count the pairs of nerves, and it would seem scarcely 

 possible that he should not have traced the cord to its termina- 

 tion, which he evidently failed to do. Prof. Owen has fallen 

 into the same error with regard to length ; and having particu- 

 larly noticed the terminal ganglion in other fishes, that of the 

 Lophius could not have escaped him, had he made a careful dis- 

 section. He expressly states that it terminates in a point. 



The description of Cuvier is the only one which seems appli- 

 cable to the specimen exhibited. "The spinal marrow in gene- 

 ral," he says, "terminates near the end of the spine ; it is so in 

 Lophius, (Baudroie) as in the most of fishes." " These (the 



