How to obtain it. 



167 



in this view of the ovum as in some others. For the same reason 

 the body of the fish is not discernible, but the veins and arteries 

 of the umbilical sac are very distinct. 3 is the artery which 

 conveys the blood to the body, whilst 4 is the vein by which the 

 same blood returns to the heart. 5 represents the vein which 

 collect the blood from the capillaries or smaller veins. The 

 small dots in the veins represent the blood coursing along. The 



- 5 



Fig. 15- 



numerous rounded bodies (as No. 6) are the oil globules which 

 supply nourishment. 



The development goes on, and the embryo requires more 

 oxygen. The water supply should be gradually increased, and 

 daily attention given to the picking of the ova. When picking, 

 keep the lids off the boxes as short a time as possible, and let the 

 work be done in a modified light. A few may burst and some of 

 the contents emerge, turning white immediately as the water 

 comes in contact with the albumen. This is an excellent time 

 for looking over the grilles and picking out any " blind " eggs 



