xiv Illustrations 



PAGE 



Fig. 85. Anopheles pup^e resting at surface of water . 93 

 Fig. 86. Salt-marsh mosquito (Ochlerotatus lativittatus); 



male 98 



Fig. 87. Salt-marsh mosquito (0. lativittatus); female . . 98 



Fig. 88. Top-minnow (Mollienisia latipinna) 99 



Fig. 89. Dragon-flies 99 



Fig. 90. The young (nymph) of a dragon-fly 100 



Fig. 91. The cast skin (exuvce) of a dragon-fly nymph . 100 



Fig. 92. Diving-beetles and back-swimmers 101 



Fig. 93. Killifish (Fundulus heteroliatus) 102 



Fig. 94. Stickleback (Apeltes quadracus) 102 



Fig. 95. An old watering-trough, an excellent breeding- 

 place FOR MOSQUITOES 103 



Fig. 96. Horse and cattle tracks in mud filled with 



WATER 108 



Fig. 97. A malarial mosquito {Anopheles maculipennis) 



male 108 



Fig. 98. A malarial mosquito {A . maculipennis) female . 109 

 Fig. 99. Diagram to illustrate the life-history of the 



malarial parasite iio 



Fig. 100. Malarial mosquito (A. maculipennis) on the wall hi 

 Fig. ioi. Malarial mosquito (4. maculipennis) standing on 



a table in 



Fig. 102. Salt-marsh mosquito (0. lativittatus) standing on 



a table 118 



Fig. 103. Anopheles hanging from the ceiling .... 118 



Fig. 104. Yellow fevtcr mosquito (Stegomyia calopus) . . 122 



Fig. 105. Rat-flea (Lcemopsylla cheopis) ; male 152 



Fig. 106. Rat-flea (L. ckeopis) ; female 152 



Fig. 107. Head of rat-flea showing mouth-parts ... 153 



Fig. 108. Human-flea (Pulex irritans); male 153 



Fig. 109. Human-flea (P. irritans); female 156 



Fig. ho. Mouse-flea (Ctenopsyllus musculi); female . . . 156 



Fig. hi. Trypanosoma gambiense ......... 164 



Fig. 112. Tsetse-fly . 164 



