(1) The egg-rafts of Culex pipiens are laid most copiously between hours 10.30 p.m. and 12 p.m. They are also laid between 4 a.m. and 6 a.m.
(2) Fertilisation in Culex pipiens is normal. Segmentation begins in less than an hour after the deposition of the last egg.
(3) The chromosome number in the segmenting nuclei is six.
(4) A tendency to parasyndesis is exhibited by the segmenting nuclei.
(5) Parasyndesis probably effects the condition of the chromosomes in the nuclei of larva, pupa, and imago, i.e. is responsible for the presence of the apparently "haploid" character of the nuclei in the somatic cells.