472 Simon Henry Gage 



circulating blood (PI. VIII, fig. 42, E. F.). Rouleaux have 

 also l)een observed in tlie vessels of a living dog's mesenter}'. 

 A nucleus is present in all the corpuscles, but as it is small and 

 placed in the thickest part of the corpuscle, it is not apparent 

 in the perfectly fresh ones, except faintly in some of those of 

 the 9 mm. embryo. The corpuscles when fresh appear, there- 

 fore, almost exactly like those of man." So complete is the 

 resemblance, that skilled observers have frequently been con- 

 fused, and pronounced fresh preparations of lampre3^'s blood 

 to be mammalian. As seen in the table, however, the num- 

 ber of the white corpuscles is proportionally very much greater 

 than in mammalian blood, and the white corpuscles are almost 

 always smaller than the red ones, thus standing in the.se two 

 particulars in marked contrast with mammalian blood. Fur- 

 thermore "no element of uncertainty should arise with respect 

 to them in legal medicine, for (a), the presence of a nucleus 

 may be readily demonstrated, as it is made apparent by dry- 

 ing, by acetic acid, and by the reagents most used in exam- 

 ining blood for medico-legal purposes ; {b), except in the em- 

 bryo 9-10 mm. long, the corpuscles are nearly twice as large 

 as those of man. (Compare the accompanying table of meas- 

 urements). Hence the red blood corpuscles of lamprey eels, in 

 spite of their bi-concave form and circular outline, really offer 

 no more difficulty in medical jurisprudence than do the cor- 

 puscles of any other of the non-mammalian vertebrates.* 



" The circular outline of the red blood-corpuscles in both 

 adult and larval lampreys was discovered by R. Wagner and 

 the fact published in 1838 ('38). 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. This feature, as in mam- 

 mals, is lost soon after death. 



' ' Although the bi-concave character of the corpuscles of 

 lampreys is as easily demonstrated as in the corpuscles of 



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

 the developing corpuscles in the adult are nucleated, the size and uni- 

 formly nucleated condition of the corpuscles of the lamprey would 

 sufficiently characterize them. 



