Plate V 



Camera drawings of typical specimens of the four strains of Series I on hatching or at a period 

 equally advanced. 



H represents a typical specimen of pure bred F. heteroclitus on hatching. 



/; represents an average specimen of the hybrid strain, F. majalis c? and F. heteroclitus 9. 



m represents a well developed specimen of the hybrid strain F. heretoclitus c?" and F. majalis 9 

 after 27 days development, after nearly all of the pure F. majalis strain had hatched. The size and 

 general appearance of this type of hybrid is almost identical with those of the paternal species, 

 F. heteroclitus, although the embryo developed from a F. majalis egg. The large mass of surplus 

 yolk, which the embryo is unable to assimilate is seen beneath the head and trunk. 



M represents a typical specimen of pure bred F. majalis on hatching. 



All figures drawn to the same scale, showing a magnification of 12 diameters. 



