Blastospheres [noun]

When the egg of Amphioxus is in the blastosphere stage we cannot speak of either an epiblast or hypoblast.

The hollow sphere which is thus formed is the important stage of the “germinal vesicle,” the blastula, or blastosphere.

Thus, an oval and an elongate egg produce respectively an oval and an elongate blastosphere.

A limit is set to increase in the size of a blastosphere by the nature of the material of its walls.

The central part of the blastosphere is called the segmentation cavity or blastocoel.

The cells of the blastosphere may divide themselves by a process of concentric splitting into two layers (fig. 56, 3).

The segmentation results in the formation of a single-walled blastosphere with a large central cavity (fig. 68 A).

In the first of these segmentation results in the formation of a blastosphere.

The segmentation is regular and leads to the formation of a blastosphere with a large segmentation cavity.

There is a regular segmentation resulting in the formation of a blastosphere with a central segmentation cavity.