29G 



THE LANCELET. 



apparently as an organ of prehension, and the tongue is supplied with a double row of smaller 

 but powerful teeth on each side, acting on the jirinciple of a ras]5. The Myxine can scarcely 

 be said to jjossess any bones, the only indi(-ation of a skeleton being the vertebral column, 

 which is nothing more than a cartilaginous tube, through which a jirobe can be passed in either 

 direction. The structure of the breathing-organs is very remarkable. A double row of 

 branchial cells take the place of gills or lungs, and are supplied with water through a spiracle 

 in the upper part of the head, and two little apertures on the under surface. 



The color of the Hag-fish is dark brown above, taking a paler tint on the sides, and 

 grayish-yellow below. Its length is generally about a foot or fifteen inches. 



The last of the fishes is a creature so unfish-like that its real position in the scale of nature 

 was long undecided, and the strange little being has been bandied about between the vertebrate 

 and iuvert«l)rate classes. Between these two great armies the Lancelet evidently occupies 

 the neutral ground, its structure partaking with such apparent equality of the characteristics 

 of each class, that it coidd not be finally refeired to its proper rank until it had been sub- 

 mitted to the most cai'eful dissections. In fact, it holds just such a jjosition between the 

 vertebrates and invertebrates as does the lepidosiren between the rei)tiles and the fishes. 



It has no definite brain, at all events it is scarcely better defined than in many of the 

 insect tribe, and is only marked by a rather increased and blunted end of the spinal cord. It 

 has no true heart, the place of that organ being taken by i)ulsating vessels, and the blood being 



X,ANCELBT.— ^m^io-xu* lanceolatia. 



quite pale. It has no bones, the muscles being merely attached to soft cartilage, and even the 

 spinal cord is not protected by a bony or even horny covering. The body is very transparent, 

 and is covered by a soft delicate skin without any scales. There are no eyes, and no apparent 

 ears, and the mouth is a mere longitudinal fissure under that part of the body which we are 

 compelled, for want of a bettin- term, to call the head, and its orifice is crossed by numerous 

 cirrhi, averaging from twelve to fifteen on each side. Altogether, it really seems to be a less 

 perfect and less developed animal than many of the higher mollusks. 



