Popis: |
A study was made of the blood elements essential for the maturation of eggs of anopheles mosquitoes. The results may be briefly summarized as follows:— 1. 1. Blood contains a factor which is necessary for the maturation of eggs of A. elutus. 2. 2. Neither haemoglobin alone nor serum alone is capable of inducing egg maturation. 3. 3. Haemoglobin can bring the ovaries to stage II of their development but no further; in this respect it serves as do raisins and sugar. 4. 4. If anopheles whose ovaries are at stage II are fed on serum, then complete ripening of the ovaries occurs. 5. 5. The specific egg-maturing factor is found, therefore, in the stroma of the erythrocytes as well as in the cell-free serum. 6. 6. This factor is still active after the serum has been heated at 100° C. for 1 hour. 7. 7. In serum coagulated by boiling the specific factor is associated with the coagulum and is absent in supernatant fluid. 8. 8. Lipoids extracted from serum or red cells are inactive, whereas the extracted serum is still active. 9. 9. It is not clear whether we are dealing with an accessory substance or with the specific action of the protein itself. It is clear that the substance is heat-stable, and is associated intimately with the serum protein and cell stroma. It appears also that a certain quantitative relation exists because, when the serum is diluted progressively, fewer and fewer of the anopheles fed mature their ovaries. |