1. The material has been obtained from parthenogenetic females. In Thrinax macula at least two kinds of females exist, one male-producing, the other female-producing. In Allantus pallipes males have not been found.

2. In the early oocytes of Thrinax macula the nucleoli are basophil; as they increase in size they develop an oxyphil margin. Later, the oxyphil part becomes rounded off and separates from the basophil. The basophil nucleolus now consists of a small basophil body surrounded by a basophil or slightly oxyphil portion. Vacuoles appear in the outer part, and become larger, in some cases containing dark granules which probably originate from the darkly staining body. The granules increase in size and ultimately become liberated as separate bodies, consisting of a basophil part surrounded by more faintly staining material. These buds may also originate from large vacuolated masses given off from the basophil nucleolus. The buds pass towards the periphery, but were not observed in the ooplasm or passing through the nuclear membrane. They apparently disappear after yolk-formation has commenced; the basonucleolus persists but seems to lose its granules.

3. As the basophil buds are being formed the oxyphil nucleolus enters upon a period of activity, numerous oxyphil buds being liberated.

In some cases the oxyphil buds originate from a vacuolated mass as large as the oxyphil nucleolus, and which arose, probably by constriction, from the latter. Oxyphil buds were observed to migrate towards the nuclear membrane.

4. In Allantus pallipes the nucleoli of the early oocytes are basophil; later, they stain more faintly and finally become oxyphil. In the fully formed oocyte before yolk-formation the basophil material is only represented by small bodies containing dark granules. These bodies may be present during the later stages of yolk-formation, when in some cases they occur as basophil bodies without any granules. In one instance a similar body was observed outside the nuclear membrane.

The oxyphil nucleolus becomes active before yolk-formation commences; it becomes more marked in the later stages and in many cases the nucleolus appeared to be breaking up. The buds occurred in close contact with the inner surface of the nuclear membrane and, later, somewhat similar bodies were observed in the ooplasm; the latter, however, were difficult to differentiate from the smaller yolk-globules.

5. The origin and behaviour of the oxyphil emissions are similar in both species. The oxyphil buds apparently pass into the ooplasm and are utilized during yolk-formation. The basophil buds of Thrinax macula and the basophil bodies of Allantus pallipes originate from the basonucleolus. The occurrence of basophil bodies without granules in older oocytes, and the presence of one body in one case outside the nuclear membrane of an Allantus oocyte suggest that these bodies lose their granules, and are then extruded into the ooplasm, where they play some part in the nourishment of the oocyte.

This content is only available via PDF.