te 
138 The Significance of Sex. [ Feb. 
travelled round Greenland from the north, while the West Green- 
landers came down southward along the shores of Baffin’s Bay, 
meeting the others at the southern point of Greenland, and there 
forming a mixed race. The author considers that the differences 
described favor this hypothesis, but thinks it too early to draw 
a general conclusion from the facts at hand. He adds that the 
mixed race in all probability also contains Scandinavian elements, 
though not the slightest trace of Scandinavian culture is to be 
discovered. 
In a foot-note at the beginning of the article Dr. Rink states 
that the direct inspiration of the paper was the fact that he had 
the opportunity of studying the rich ethnological collection from 
East Greenland in company with Captain Holm, and also per- 
sonally received information about the western Eskimos from the 
brothers Krause and A. Jakobson, and about those of the middle 
region from Dr. F. Boas. He also courteously acknowledges 
the information received from other sources, especially from those 
in America who are engaged in studying similar subjects. 
U. S. NATIONAL MUSEUM. 
THE SIGNIFICANCE OF SEX. 
BY JULIUS NELSON. 
(Continued from page 42.) 
EXPLANATION OF PLATES VI.—VIII. 
Figs. 94 to 124, 4, illustrate cell-division (94-104 are Protozoan), and Figs. 
124, 7,-133 ENER fertilization (ż.e., the union of male and female pronuclei). 
PLATE VI. 
FIG. 94, a-b. Opalina ranarum—Kent, Plate 26. See also Nussbaum, A. m 
vi., and Zeller, Z. w. Z., xxix.—This “ unicellular” animal is multinucleate, a 
the nuclei maltiply by karyokinesis (see Figs. 104, 105) independently of cell- divis- 
ion. The latter takes place successively as in a, until small cells like 4 Sage con- 
taining few nuclei. These become encysted and the nuclei fuse to becom 
Then the mononucleate animal escapes and increases in size, roast the sa ibe 
come more numerous . Their number may rise to | 
again. 
Fic. 95, a-d. Oxytricha scutellum—Gruber, Z. w. Z., mei this infusorian 
ki am PS 7 een the groups of nuclei as shown in g and 4. 
one Polyericus sche i Ai ix.—This infusorian 
grows the amber of nuclei i increases aig comes division, w ye have a form like ¢, 
wt FTA 
