STUDIES [N THE EXUDETMENTAE ANALYSTS OF SEX. 169 
Literature. 
1. Gnyei', M. F. — “On the Sex of Hybrid Birds,” ‘Biological Bulletin,' 
vol. xvi, 1909, p. 193. 
2. “ Spermatogenesis of Normal and of Hybrid Pigeons," Dis- 
.sertation at the University of Chicago, 1900. 
3. “ The Spermatogenesis of the Domestic Chicken,” ‘ Anato- 
mischer Anzeiger,’ Bd. xxxiv, 1909, p. -573. 
4. “ Tlie Spermatogenesis of the Domestic Guinea,” ‘ Anato- 
mischer Anzeiger,’ Bd. xxxiv, 1909, p, 502. 
EXPLANATION OF PLATE 8. 
lllustratino- Mr. OcofTrey Smitlihs paper on “ Stiulie.s in the 
Experimental Analy-sis of Sex.” 
[All the figures are drawn with the camera under a 4 eyepiece and a 
^U-in. objective. Magnification about 1270. The tails of the sperma- 
tozoa are sOTuewhat schemati.sed, but the heads give accurate pro- 
portions. All jireparations fixed in corrosive-acetic and stained with 
iron-hannatoxylin.] 
Fig. 1. — Spermatozoa of normal domestic dove. 
Fig. 2. — Siierinatozoa of normal pigeon. 
Fig. 3. — Spermatozoa of hybild A between pigeon and dove ? . 
Fig. 4. — Ditto of hybrid B. 
Fig. 5. — Ditto of hybrid C. 
Fig. (i. — Stages in spermatogenesis of normal pigeon, (i «. First 
maturation division, showing about eight sube(jual chromosomes on 
erpiatorial plate, (i b. Second maturation, showing tour chromosomes. 
•> c. Resting spermatids. (J il. Maturing sj ermatids in transverse 
section with a nurse-cell or cell of Sertoli. 
Fig. 7. — Spermatogenesis in another normal pigeon. 7 a. Fii-st 
maturation division. 7 b. Second maturation division. 7 c. Resting 
spermatids. 7 <1. A nearly mature spermatid in longitudinal section, 
and two in transverse section. 
Fig. 8. — Spermatogenesis in normal dove. Two first maturation 
divisions, one second maturation division, three resting spermatids, and 
three maturing spermatids. 
