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Chapter XFII 

 ANOPHELINAE THE OVUM 



THE OVUM 



Anophelines in captivity generally lay their eggs 

 on some floating object, but also upon the surface of 

 the water. When laid on a solid object, and even 

 when laid on the water, the eggs are deposited in a 

 piled up mass. Later, the ova, if on water, often form 

 very regular and beautiful patterns. Brick-red masses 

 of eggs are sometimes laid. These do not develop 

 further. 



Observe (i) the arrangement in equilateral triangles 

 and star patterns (Fig. 24). 



(ii) The arrangement in rows of eggs lying side 

 by side. 



Both patterns are dependent upon the shape of 

 the individual ovum ; ova belonging to type I forming 

 stars, and ova belonging to type 2, rows. 



The number of ova varies, but is usually about 

 one hundred. The size of the ovum varies with 

 different species from about 0*6 to ro mm. 



Duration of Egg Stage. Temperature is no doubt 

 an important factor. Thus the egg stage in A. 

 maculipennis lasts from two to four days, whereas in 

 Ce. argyrotarsis it is one and a half days in Havana. 

 In M. rossi it is about forty-eight hours. 



Anopheline ova (with one or two exceptions as 

 yet described) are boat shaped, with an approximately 



