GO 
Franz Schräder 
6. The somatic cells of the male partake of the characteristics of 
the spermatocytes but to a lesser extent. The somatic cells of the female 
however are not exceptional in any of their varicus phases. 
7. The spermatogonial divisions of P. citri seem to show none of the 
peculiarities observed in the spermatocytes. In the spermatogonia of 
P. nipae however, there is evidence that similar phenomena occur. The 
follicle and oogonial cells do not share such peculiarities in any of the 
three species. 
8. In the maturation of the eggs, five tetrads of normal appearance 
are evolved. 
References cited. 
McGillivray, A. 1921. The Coccidae. 
JIeves, F. 1907. Die Spermatocytenteilungen bei der Honigbiene (Apis mellifica), 
nebst Bemerkungen über Chromatinreduktion. Arch. mikr. Anat., Bd. 70. 
— und Duesberg, J. 1908. Die Spermatocytenteilungen bei der Hornisse (Vespa 
crabro L.). Arch. mikr. Anat., Bd. 71. 
Mohr, 0. L. 1914. Studien über die Chromatinreifung der männlichen Geschlechts- 
zellen bei Locusta viridissima. Arch. d. Biologie, T. 29. 
— 1915. Sind die Heterochromosomen walire Chromosomen? Arch. f. Zellf., Bd. 14, 
PiERAXTOXi, U. 1913. Studii sullo svilluppo d’Icerya purchasi Parte II. Arch. Zoolog. 
Itah, T., 7. 
Schräder, Fraxz. 1920. Sex-determination in the White-Fly (Trialeurodes vapora- 
riorum). Journ. Morph., Vol. 34. 
— 1921. The chromosomes of Pseudococcus nipae. Biol. Bull., Vol. 40. 
Wilson, E. B. 1905. Studies on chromosomes I and II. Journ. Exp. Zool. Vol. 2. 
— 1909. Studies on Chromosomes IV. Jour. Exp. Zool. Vol. 6. 
— 1912. Studies on Chromosomes VIII. Jour. Exp. Zool., Vol. 13. 
Drawings made at table level, using Zeiss Xo. 12 ocular and 2 mm. oil Immersion 
objective. Magnification approximately 3200. 
Plate V. 
Pseudococcus maritimus. 
First spermatocyte. 
Fig. 1. Resting phase, showing dense and loose chromatin, and nucleolus. 
Fig. 2. Early condensation phase with split first appearing in the chromosomes 
evolving from the dense chromatin. 
Fig. 3. Fiuther condensation ofclumped chromosomes. Nucleolus decreasing in size. 
Fig. 4. Early condensation stage of loose group of chromosomes, which are double 
‘or split at this stage, 
