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EXPLANATION OF PLATES IX AND X 
All figures show a magnification of about 1600, excepting fig. 25, which 
is about 1200. 
Fic. 1.—Complete view of very early E.S.M.C., showing about thirteen 
paired centers of chromatin aggregation. 
Fic. 2.—Partial view of similar nucleus. _ 
Fic. 3.—E.S.M. nucleus entering synizesis, showing curious partly paired, 
partly vacuolate appearance of chromatin masses. 
Fic. 4.—Unusually large E.S.M.C. at climax of synizesis. 
Fic. 5.—E.S.M.C. emerging from synizesis, showing uniform character of 
thread. 
Fic. 6.—The same, somewhat later. 
Fic. 7.—The same, thread becoming less homogeneous. 
Fic. 8.—The same, thread showing dual character in places. 
Fic. 9.—The same, segmentation beginning, thread thicker and dual 
character obvious in most nodes. 
Fic. 10.—P.M.C. showing segmentation and dual nodes 
Fic. 11.—E.S.M.C., chromosomes becoming becsouensien, duality mainly 
visible at internodes. 
Fic. 12.—The same, showing origin of cuboid chromosome form; thicken- 
ing of thread producing contraction of mass toward center. 
Fics. 13a, b.—Complementary sections of same E.S.M. nucleus, with 
twenty-six (diploid number) chromosomes, cuboid and with traces of dual 
internodes still showing. 
Fics. 14a, b.—The same, somewhat later, showing various retractions and 
shiftings of quadruple internodal traces 
Fic. 15.—Part of P.M.C. at same does as preceding 
Fic. 16.—Complete P.M.C., showing beginning of ext to end synaptic 
pairing of twenty-six univalent culos: 
Fic. 17.—Late orientation stage in sequence A, E.S.M.C. showing synap- 
sis completed. 
Fic. 18.—Same for P.M.C. 
