THE ROBIN. 159 
the effect of hunger being increased perhaps by the cold, 
as the thermometer was about sixty degrees. 
The other bird, still vigorous, he put in a warmer place, 
and increased its food, giving it the third day fifteen worms, 
on the fourth day twenty-four, on the fifth twenty-five, on 
the sixth thirty, and on the seventh thirty-one worms. They 
seemed insufficient, and the bird appeared to be losing 
plumpness and weight. He began to weigh both the bird 
and its food, and the results were given in a tabular form. 
On the fifteenth day, he tried a small quantity of raw meat, 
and, finding it readily eaten, increased it gradually, to the 
exclusion of worms. With it the bird ate a large quantity 
of earth and gravel, and drank freely after eating. By the 
table, it appears that though the food was increased to forty 
worms, weighing twenty pennyweights, on the eleventh day 
the weight of the bird rather fell off; and it was not until 
the fourteenth day, when he ate sixty-eight worms, or thirty- 
four pennyweights, that he began to increase. On this day, 
the weight of the bird was twenty-four pennyweights: he 
therefore ate forty-one per cent more than his own weight 
in twelve hours, weighing after it twenty-nine pennyweights, 
or fifteen per cent less than the food he had eaten in that 
time. The length of these worms, if laid end to end, would 
be about fourteen feet, or ten times the length of the intes- 
tines. 
To meet the objection, that the earthworm contains but a 
small quantity of nutritious matter, on the twenty-seventh 
‘day he was fed exclusively on clear beef, in quantity twenty- 
seven pennyweights. At night, the bird weighed fifty-two 
pennyweights, but little more than twice the amount of flesh 
consumed during the day, not taking into account the water 
and earth swallowed. This presents a wonderful contrast 
with the amount of food required by the cold-blooded ver- 
tebrates, fishes, and reptiles, many of which can live for 
months without food, and also with that required by 
mammalia. Man, at this rate, would eat about seventy 
