The Lake and Brook Lampreys of New York 473 



mammals, it is stated by Gulliver and Giinther that they are 

 flat or bi-convex, and Gegenbauer in his Comparative Anatomy, 

 states that the red blood-corpuscles of birds, reptiles, amphibia, 

 and fishes are bi-convex, no exception being made for the lam- 

 preys. Parker in his translation of Wiedersheim's Compara- 

 tive Anatomy of the Vertebrates, says : ' In case of the red 

 corpuscles, the nucleus persists, and the whole cell is bi-con- 

 vex in all vertebrates below mammals.' In 1887 wide circula- 

 tion was given to a statement by Shipley ('87), and Thomp- 

 son ('87), that the red blood-corpuscles of larval lampreys 

 were oval in outline, like the rest of the non-mammalian ver- 

 tebrates." 



And Thompson further adds : ' ' The noteworthy point now 

 is, that myxine possesses red corpuscles similar to those, not 

 of the adult, but of the larval lamprey, which in many ways 

 it resembles otherwise." On consulting the original article 

 by Shipley ('87), the statement is found to be : "The blood 

 corpuscles are of only one kind, large oval disc-like structures, 

 with a well-marked nucleus." The size of the embryo is 

 not given, but it was in the stage before the white blood-cor- 

 puscles appear. As all observers have noted the tendency of 

 the red corpuscles to become deformed, one can readily under- 

 stand that, if the form were observed in sections, from mutual 

 compression the corpu.scles would not remain of circular form. 

 If Dr. Shipley examined these corpuscles in the serum of the 

 larva and in the living condition, and they were found oval 

 instead of circular, the fact would be exceedingly interesting 

 and perhaps suggestive. One would hardly expect to find 

 embryonic blood-corpuscles oval, for even in animals in which 

 the red corpuscles of the adult possess an extreme elliptical 

 form the embr3'onic ones are either circular or approximately 

 so (Kolliker '84. Milne-Edwards). 



" That the red blood-corpuscles of both the adult and larval 

 lampreys are circular, bi-concave, nucleated discs, as here de- 

 scribed and figured, was repeatedly demonstrated in larvse 

 from 9 to 142 mm. long, and in numerous adults. In every 

 specimen examined all the corpuscles not irregular were cir- 

 cular in outline. To make sure that this appearance was not 



