SOME ASPECTS O F T H E BIOLOGY O F T H E CHAETOGNATHS
341
into the lumen of the vagina (Fig. 33). Since, however, there is a
considerable reorganization of all the cellular tissue and the phenomenon is very quick, it is not possible to ascertain in vivo whether the
eggs actually enter into the lumen of the vagina or-as happens with
Xagitta-end by penetrating between the two layers of cells which form
its wall. It can in any case be safely ruled out that the eggs pass, as
FIG. 33. A diagram of the laying of the eggs in Spudella cephuloptera. To the right
(arrow) an egg is piercing1 through the epithelial wall of the vagina v, to enter the
short temporary oviduct. To the left an egg is passing to the outside. The position
of the seminal pouch s.p. is indicated seen through the eggs; oc young oocytes;
i intestine ; go genital opening; s.r. seminal receptacle ; t testis; 1. f. lateral fins.
John (1933) said, into the seminal receptacle : in order t o pass t o the
outside they always come in contact with the walls of the vagina and
never with those of the receptacle which, during the passage of the
eggs, may be pushed towards the median line of the body. It should
be remembered in this connexion that the vagina is placed at a right
angle t o the line of the body; in the middle of it lies the spherical
shaped seminal receptacle, followed by the pouch which runs parallel
with the intestine. Also, observations with the phase contrast microscope have shown that the walls of the seminal receptacle always
341
into the lumen of the vagina (Fig. 33). Since, however, there is a
considerable reorganization of all the cellular tissue and the phenomenon is very quick, it is not possible to ascertain in vivo whether the
eggs actually enter into the lumen of the vagina or-as happens with
Xagitta-end by penetrating between the two layers of cells which form
its wall. It can in any case be safely ruled out that the eggs pass, as
FIG. 33. A diagram of the laying of the eggs in Spudella cephuloptera. To the right
(arrow) an egg is piercing1 through the epithelial wall of the vagina v, to enter the
short temporary oviduct. To the left an egg is passing to the outside. The position
of the seminal pouch s.p. is indicated seen through the eggs; oc young oocytes;
i intestine ; go genital opening; s.r. seminal receptacle ; t testis; 1. f. lateral fins.
John (1933) said, into the seminal receptacle : in order t o pass t o the
outside they always come in contact with the walls of the vagina and
never with those of the receptacle which, during the passage of the
eggs, may be pushed towards the median line of the body. It should
be remembered in this connexion that the vagina is placed at a right
angle t o the line of the body; in the middle of it lies the spherical
shaped seminal receptacle, followed by the pouch which runs parallel
with the intestine. Also, observations with the phase contrast microscope have shown that the walls of the seminal receptacle always