V. Evaluation of Cross-Immunity against Type 1 Dengue Fever in Human Subjects Convalescent from Subclinical Natural Japanese Encephalitis Virus Infection and Vaccinated with 17D Strain Yellow Fever Vaccine
The study of the effects of Chara fragilis (fig. 1) on mosquito development reported in 1928 (6) has been continued and expanded during the past season. Our investigations were directed along five principal lines: (a) Continued studies of the effects of Chara fragilis on larval development under experimental conditions. (b) A survey of a portion of the central New York area to determine the distribution of Chara spp. and their effect on mosquito density. (c) The introduction of Chara fragilis into various types of ponds, marshes, etc., to study its rate of growth and effect on future mosquito breeding. (d) A continued study of the food (plankton) in Chara ponds and typical mosquito breeding pools. (e) The effects of other aquatic plants on the larvae of Culicidae.
The results of this season's work can be presented best under these five headings.