452 ELMER L. SHAFFER. 



ture. The egg-strings of the oocytes pass up into the nurse 

 chamber and serve to carry the nutrient materials to the oocytes. 

 In the ovaries of the adult, the nurse-cells are ingested at the 

 upper end of the egg-string and their ingested products pass down 

 into the oocyte as nutrient materials. 



13. Mitochondria are found in the young oocytes as a deeply 

 staining mass of granules lying in the cytoplasm at one pole of 

 the nucleus. In the later stages the mitochondria gradually 

 extend around the nucleus forming a perinuclear zone of mito- 

 chondria. 



14. The mitochondria increase greatly in numbers during the 

 postsynaptic stages still retaining their perinuclear arrangement. 



15. When the cytoplasmic volume of the oocyte has reached 

 its maximum, the perinuclear arrangement of the mitochondria 

 becomes lost and the mitochondria become dispersed toward 

 the periphery of the oocyte. 



1 6. At the periphery of the oocyte, the mitochondria become 

 transformed into yolk-spherules. First vacuoles are found sur- 

 rounding the mitochondria, these structures resembling the 

 "pseudo-nuclei" of Blochmann. The substance of the vacuoles 

 at first takes the plasma stain lightly and as it grows in size, it 

 becomes more and more deeply staining. The globules increase 

 greatly in size and show a marked affinity for the basic stains. 



17. The relation betw r een the perinuclear zone of mitochondria 

 and such structures as yolk-nuclei, etc., is pointed out. 



1 8. The zone of the cytoplasm immediately surrounding the 

 nucleus is taken to be the locus in the cell of the formation of 

 mitochondria through the chemical action of the nucleus upon 

 the products of assimilation taken in by the cytoplasm. 



LITERATURE CITED. 

 Athias, M. 



'19 Recherches sur les cellules interstitielles de 1'ovaire des Cheiropteres. 



Arch, de Biol., T. XXX. 

 Boring, A. M. 



'07 A Study of the Spermatogenesis of Twenty Species of the Membracidae, 



Jassidae. Cercopidae and Fulgoridse. Jour. Exp. Zool., Vol. IV., No. 4. 

 '13 The Chromosomes of the Cercopidae. BIOL. BULL., Vol. XXIV., No. 3. 

 Browne, E. N. 



'13 A Study of the Male Germ Cells in Notonecta. Jour. Exp. Zool., Vol. 14, 

 No. i. 



