222 THOMAS H. BRYCE. 



Strasburger, 1894^.— ' Annals of Botany,' vol. viii, 1894. 

 Strasbukger, 1895. — ' Jalirb. f. wiss. Bol.,' xxviii. 

 Strasburger, 1897. — 'Jalirb. f. wiss. Bot.,' xxx and xxxi. 

 Strasbukger and Mother, 1897.— 'Ber. d. Bot. Ges.,' xv, 0. 

 Stkasuurgek, 1900. — ' Uebor Rednktionsllieilung, Spiiidelljihiunfr, Ccnlro- 



sonien und Cilieiibildner im Pflanzeiuficli,' Jena, Fischer, 1900. 

 van der Stricht, O., 1898.— 'Arch. Biol.,' xv. 

 ScHULTZi!;, O., 18S7. — ' Zeitschnfl, f. wiss. Zool.,' xlv. 



Watase, 1892-3. — ' Journ. of Morphology,' viii, "Wood's HoU Lcclures." 

 VVeissmann, 1893 — 'The Gcrniplasm,' English t ian!>lal,ion. 

 Wheeler, W. M., 1897.—' Arch, de Biologie,' xv. 

 Whitman, C. O., 1878. — 'Quart.. Journ. Micr. Sci.,' vol. xviii. 

 Wilcox, E. V., 1895. — ' Bull. Mus. Conip. Zool. Harvard Coll.,' xxvii and xxix. 

 Wilson, Ed. B., 1895 (1). — ' Atlas of Fertilization, etc.,' New York. 

 Wilson, Kn. B., 1895 (2). — ' Journal of Morphology,' xv. 

 Wilson, Ed. B., 1897.—' Science,' vol. v, No. 114. 

 Wilson, Ed. B., 1899. — 'Journal of Morphology,' xv (supplement). 

 Wilson, Ed. B., 1900.—' The Cell, etc.,' Macmillan, 2nd edit., 1900. 

 ZoJA, 1895. — ' Anat. Anzeiger,' xi, 10. 



EXPLANATION OF PLATES 10—12, 



Illustrating Dr. Bryce's paper ou " Maturation ot the Ovum 

 in Echinus esculent us." 



All the figures were drawn by aid of the camera lucida with Zeiss 3 mm. 

 apochromatic objective of 1'40 mm. aperture (homogeneous immersion), and 

 G, 8, or 12 compensating ocular. The magnification, tested by the stage 

 micrometer, of Figs. 1 to G is 850, of the remainder 1200, except Fig. 20, 

 which is magnified 1500 times. The drawings represent as realistically as 

 possible wiiat can be seen in the individual section, and, except in Fig. IS, no 

 attempt has been made to make the drawing diagrammatic by incorporating 

 data from two or more sections of the same ovum. A series of jihoto-niicro- 

 graplis of the stages, kindly taken for me by Dr. J. H. Teacher, was of con- 

 siderable assistance for comparison with, and verification of, the drawings. 



