go SOME MINUTE ANIMAL PARASITES 



and gnats, practically all females, and they have come 

 to the water to lay their eggs. One may be the tiny, 

 grey-striped " Scot's Grey gnat " the Stegomyia 

 responsible for yellow fever. This ghostlike insect, 

 though almost ubiquitous, prefers smaller quantities 

 of water. Far more obvious are other gnats (Culi- 

 cines) and the true mosquitoes (Anophelines), and 

 woe betide bird or man respectively that happens to 

 be in the neighbourhood when these insects wish to 

 lay their eggs. For the egg-laying, demands much 

 energy, and the source of energy for the gnat is the 

 blood of the bird, and a meal of human blood is the 

 best aid to the female mosquito in discharging her 

 creative function, and in providing the strength for 

 placing her many eggs in the medium most suitable 

 for their development. 



Examine the surface of the pool after the winged 

 insects have gone. Here and there minute oval 

 spots among the vegetation mark the eggs of the 

 Cidex, often called the " house mosquito," or " hou >e 

 gnat." These brownish eggs are bound together into 

 a raft and float on the water with their more pointed 

 ends upwards. In contrast, scattered masses of some- 

 what boat-shaped Anopheline eggs, lying irregularly 

 on the surface, can be found with the aid of a lens. 

 Much the same size as the eggs of the Culex, they do 

 not form rafts, but form patterns (stars, triangles, 

 rows) on the surface, sometimes near water-weed, if 

 such be available. 



Watch the water the next day or so, and instead of 

 passively floating rafts or eggs, numbers of minute 

 wriggling forms are seen. These are the freshly 



