590 
DR. NELSON ON THE REPRODUCTION OF THE ASCARIS MYSTAX. 
Fig. 42. The upper constriction, or that between the ovary and oviduct, h. The ex- 
ternal membrane of the lower portion of the ovary without strise. in. The 
constriction where the ovary ends and the oviduct commences, n. The 
transverse strise of the oviduct, by which the ovules are forced along singly, 
o. An ovule detached from the general mass filling the ovary, and about to 
enter the oviduct, p. The spermatic particles fully developed, occupying 
the whole length of the oviduct. 
Fig. 43. A small portion of the uterus, h. The external transparent and structure- 
less membrane, r. Large flat cells by which it is lined, s. The nuclei, 
and t. The nucleoli of these cells. 
Fig. 44. Contents of the csecal portion of the ovary, a. The germinal spot, which 
is solid, h. The germinal vesicle, transparent, containing a fluid and the 
germinal spot, -j-- The germinal particle as first throwm off, the swelling 
up of whose outer layer forms the germinal vesicle, while the central por- 
tion remains unaltered to form the germinal spot. 
Figs. 45, 46. Ovula at a very early stage of development, a. The germinal spot. 6. The 
germinal vesicle, whose margin however is not visible, c. The vitelline 
granules surrounding the vesicle, and apparently the produce of the walls 
of the ovary, d. The clear gelatinous substance in which the granules are 
imbedded, and which forms the margin of the ovule. 
Fig. 47 . An ovule further advanced, of a triangular form. a. The germinal spot. 
b. The germinal vesicle, c. The vitelline granules, d. The clear sub- 
stance forming a distinct outline. 
PLATE XXVIII. Magnified 330 diameters. 
Fig. 48. An ovule still further developed, presenting a discoidal form. a. The ger- 
minal spot. h. The germinal vesiele. c. The vitelline granules, d. The 
clear substance. 
Fig. 49. Mass of ovules squeezed out of the ovary, b. Ovula seen on their flattened 
surface, and showing the contained germinal vesicles, c. Ovula in the na- 
tural position they occupy in the ovary, presenting only their edges exter- 
nally. d. The external portions of the flat ovules, which lie against the 
wall of the ovary. 
Fig. 50. Portion of the ovary at its inferior extremity, showing the disposition of the 
contained ovules, d. Four ovula forming one plane, and exactly filling the 
transverse section of the ovarian tube. w. The wall of the ovary containing 
a few granules. 
Fig. 51, A fully developed ovule, of an elliptical or ovoid form, and in the state in 
which it leaves the ovary to enter the oviduct, c. The vitelline granules. 
