VITELLINE MEMBRANE AND CORTICAL PARTICLES 299
that remained expanded (see Runnström, 1962, Figs. 16-18). The two
states of fenestrated membranes correspond to the assumed states outlined in Figs. 32A and B.
The curls have perhaps been somewhat overemphasized above as basis
for the connections within the lamellae. They could be called terminal
connections, but there are also intralamellar connections between the
filaments; see, for example, Fig. 7, Section Ι,Β,Ι. These seem to remain
even when the lamellae have been released from the extralamellar bodies
(Figs. 27 and 30). They are still maintained in the pivotlike stage. A
partial or complete breakup occurs, however, during the sliding process.
As reported in Section II,C, sudden warming of the eggs at 10-15 sec
after insemination to 32°C for 3-4 min may interrupt the activation
impulse, with partial fertilization as a consequence. In an even higher
percentage of the eggs subjected to warming, the activation impulse
progresses over the whole egg surface, but the activation does not attain
the normal level. The fertilization membrane and the hyaline layer
become normal only in the region of sperm entrance. From a certain
proximal-distal level on, the fertilization membrane eeems thinner and
less elevated (Runnström, 1959b) ; particularly, the development of
the hyaline layer seems inhibited. The extralamellar bodies must remain
at the bottom of the opened cortical hollow, probably in the stage shown
in Fig. 27 (electron microscopy has not yet been adopted to the study
of the warmed egg). This means that the transfer of attachment of the
extralamellar bodies from the bottom of the hollows to the top of villi
has failed to occur. The phase-contrast observations indicate that the
normal elongation of the villi was inhibited by a sort of gelation. In
certain cases, this causes a complete block to the activation (see Section
II,C) ; in other cases, the activation impulse progresses but is not able
to bring about the full activation. The latter case refers to eggs in which
the opening of the cortical particles has been so rapid that all the cortical
particles are opened when the sudden warming sets in. Under such
conditions the breakup of the bonds between extralamellar bodies and
particle membrane becomes blocked as a consequence of a gelation
process. The "shift" (Section IV,C) from the gelated to a more solated
state is inhibited or delayed. The eggs with inhibited transformation
of the extralamellar bodies showed, when observed in phase contrast, an
interior structure distinctly different from that in normal eggs in the
stage of cleavage. Runnström (loc. cit.) suggested that the differences in
structure may be due particularly to differences in the configuration of
the endoplasmic reticulum. A swelling within this system follows upon
activation of the egg (Runnström, 1955). This is probably related to the
that remained expanded (see Runnström, 1962, Figs. 16-18). The two
states of fenestrated membranes correspond to the assumed states outlined in Figs. 32A and B.
The curls have perhaps been somewhat overemphasized above as basis
for the connections within the lamellae. They could be called terminal
connections, but there are also intralamellar connections between the
filaments; see, for example, Fig. 7, Section Ι,Β,Ι. These seem to remain
even when the lamellae have been released from the extralamellar bodies
(Figs. 27 and 30). They are still maintained in the pivotlike stage. A
partial or complete breakup occurs, however, during the sliding process.
As reported in Section II,C, sudden warming of the eggs at 10-15 sec
after insemination to 32°C for 3-4 min may interrupt the activation
impulse, with partial fertilization as a consequence. In an even higher
percentage of the eggs subjected to warming, the activation impulse
progresses over the whole egg surface, but the activation does not attain
the normal level. The fertilization membrane and the hyaline layer
become normal only in the region of sperm entrance. From a certain
proximal-distal level on, the fertilization membrane eeems thinner and
less elevated (Runnström, 1959b) ; particularly, the development of
the hyaline layer seems inhibited. The extralamellar bodies must remain
at the bottom of the opened cortical hollow, probably in the stage shown
in Fig. 27 (electron microscopy has not yet been adopted to the study
of the warmed egg). This means that the transfer of attachment of the
extralamellar bodies from the bottom of the hollows to the top of villi
has failed to occur. The phase-contrast observations indicate that the
normal elongation of the villi was inhibited by a sort of gelation. In
certain cases, this causes a complete block to the activation (see Section
II,C) ; in other cases, the activation impulse progresses but is not able
to bring about the full activation. The latter case refers to eggs in which
the opening of the cortical particles has been so rapid that all the cortical
particles are opened when the sudden warming sets in. Under such
conditions the breakup of the bonds between extralamellar bodies and
particle membrane becomes blocked as a consequence of a gelation
process. The "shift" (Section IV,C) from the gelated to a more solated
state is inhibited or delayed. The eggs with inhibited transformation
of the extralamellar bodies showed, when observed in phase contrast, an
interior structure distinctly different from that in normal eggs in the
stage of cleavage. Runnström (loc. cit.) suggested that the differences in
structure may be due particularly to differences in the configuration of
the endoplasmic reticulum. A swelling within this system follows upon
activation of the egg (Runnström, 1955). This is probably related to the