322 The Microscope. 



of those of the 9 mm. embryo. The corpuscles when fresh appear, 

 therefore, almost exactly like those of maa. No element of uncer- 

 tainty should arise with respect to them in legal medicine, however, 

 for: (a), the presence of a nucleus may be readily demonstrated, as 

 it is made apparent by drying, by acetic acid and by the reagents 

 most used in examining blood for medico-legal purposes; (6), 

 except in the embryo, 9-10 mm. long, the corpuscles are nearly 

 twice as large as those of man. (Compare the accompanying table 

 of measurements). Hence, the blood -corpuscles of lamprey eels, in 

 spite of their bi-concave form and circular outline, really offer no 

 more difl&culty in medical jurisprudence than do the corpuscles of 

 any other of the non-mammalian vertebrates.* 



The circular outline for the red blood- corpuscles of both adult 

 and larval lampreys was discovered by R. Wagner and the fact 

 published in 1838 (18). The bi-concave character is remarked upon 

 by Wagner, Kolliker and others, but I have seen no reference to the 

 fact that the corpuscles form distinct rouleaux like those of mammals. 



Although the biconcave character of the corpuscles of lam- 

 preys is as easily demonstrated as in the corpuscles of mammals, it 

 is stated by Gulliver and Gvinther (4 and 5) that they are flat or 

 bi-convex, and Gegenbauer (2), 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 lampreys. Parker 

 (15), in his translation of Wiedersheim's Comparative Anatomy of 

 the Vertebrates, says : "In case of the red corpuscles, the nucleus 

 persists, and the whole cell is bi-convex in all vertebrates below 

 mammals." In 1887 wide circulation was given to a statement by 

 Shipley (16) and Thompson (17), that the red blood-corpuscles of 

 larval lampreys were oval in outline, like the rest of the non-mam- 

 malian vertebrates, and came to be circular only in the adult. 



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

 lampreys inhabiting Cayuga Lake are circular, biconcave, nucleated 

 discs, as described and figured in this paper, was repeatedly demon- 

 strated in larvse from 9 to 142 mm. long, and in numerous 

 adults. In every specimen examined all the corpuscles not irregular 

 were circular in outline. To make sure that this appearance was 

 not due to reagents, the corpuscles were examined in the serum 

 of the blood, without the addition of any reagent whatsoever, and 

 to avoid any possible error on account of the small amount of blood 

 in the 9 mm. embryo, the circulating blood was examined. All the 



* While ic is true that the red corpuscles of mammalian embryos and the developing 

 corpuscles in the adult are nucleated, the size and uniformly nucleated condition of the 

 corpuscles of the lamprey would sufflcinntly characterize them. 



