29 



or less firm mass by a tough jelly-like substance, is almost in- 

 variably swallowed by the old bird; but it is probable that it is 

 regurgitated and thrown out after leaving the nest, since it 

 seems likely that, if left in the crop, it would become mixed with 

 the food that is gathered immediately after. If the volume of 

 excreta swallowed were small it would not necessarily be ejected, 

 but since the amount is often nearly equal to the quantity fed, 

 sometimes as high as 75 per cent, and since the feeding is done by 

 a regurgitating act, the waste matter must be thrown out. No 

 direct observation could be gotten on this point, for immediately 

 upon leaving the nest the bird would fly a considerable dis- 

 tance, very seldom stopping even within sight. 



On the evening of August 9, after dark, the entire nest was 

 taken from the tree into the house. At this time one bird had 

 opened its eyes a mere slit, while the rest had not even had a 

 peep of the world. The young were left in the nest and covered 

 with the skin of a flying-squirrel to keep them warm. 



The next morning the first meal given them consisted of 

 crackers soaked in a raw egg. The excreta from all four little 

 birds at this time was examined, in order to determine more ex- 

 actty what had been fed by the adults the day before. In it were 

 found the seeds of blue huekle berries and raspberries ; the stones 

 of two wild cherries, the elytra, cuticle and pieces of the wings 

 of several beetles. 



The first two days they were fed at least once every hour up 

 to. 7 in the evening, w^hen they were put in a warm corner and 

 covered for the night. From the third to the seventh day of 

 keeping they were fed every two hours or so, and after that every 

 three hours until they were ready to leave the nest. 



With the exception of Gallanaceous and a few Rap- 

 torian birds, the young require quantity rather than quailty of 

 food; for it passes through the digestive tract very rapidly and 

 only a small amount is really absorbed. Often a small blue- 

 berry or kernel of boiled rice would pass through intact. The 

 length of time that food is kept in the digestive tract varies in 

 young Passerine birds directly with the feeding periods. The 

 undigested particles from one feeding would not be excreted till 

 the second, third or fourth feeding after. The waste matter 

 from the evening would be all excreted at the first or second 

 feeding in the morning. If, however, food is given them at very 

 short intervals, say three to five minutes, undigested matter is 

 often excreted within fifteen or twenty minutes from the time 



