CHAPTER IX
STRUCTURAL AND DYNAMIC ASPECTS OF THE
DEVELOPMENT OF THE TELEOSTEAN EGG
CH.
DEVILLERS
I. Introduction
379
II. Structure and Development
380
III. Structural Evolution During Premorphogenesis
384
A.
Bipolar Differentiation
384
B.
The Acquisition of Structural Co-ordinates
388
C.
The Covering of the Ovum
397
D.
The Vitelline Syncytium
405
IV. Mechanics of Gastrulation
406
A.
Epiboly
7
B.
Arranging of the Marginal Material
418
V. Conclusion
1
References
4
I. Introduction
The egg of Teleosts has been less studied than that of Amphibia, yet it
has been the object of quite a large amount of work dealing mostly
with the three genera Fundulus, Oryzias and Salmo (and other Salmonidae). Interesting investigations, carried out on the eggs oiCarassius
and Brachydanio, are also to be noted, as well as isolated works on
Clupea, Perca, etc.
Some of these works have already led to general reviews: Oppenheimer (1947), and Rudnick (1955), on general and experimental
embryology; Hayes (1949) on biochemistry of the Salmon egg; De villers
(1956a) on premorphogenesis; Yamamoto (1956) on fertilization in
Oryzias; Kanoh (1957, not yet published) on activation of the egg of
Salmonidae; Smith (1957) on the first phases of development and
hatching; lastly the important bibliography of Briggs and Egami (1959)
on the egg of Oryzias.
The present review is of experimental embryology and is not intended
to repeat those of Oppenheimer and Rudnick. It is limited to the study
of the particular phases of development which show how the egg
organizes itself during the period of premorphogenesis (distribution of
constituents and co-ordinate axes), how it acquires its physico-chemical
379