13s HIKDS. 



food, showed most plainly thai the birds knew instinctive- 

 ly how to take such diet and moreover the birds <^n'\y 

 vigorous and strong upon such food. Kxpcriments like 

 these show eonclusiveh' that as a rule, at least when 

 young, the Kobin i/tii.^f l)e fed with a variety of i)iseef food 

 or die. It is not simply a matter of ehoiee, but of neces- 

 sity which causes a i)air of R()l)ins with a nest full of 

 young to catch the cut worms, canker worms and the 

 like. 



It will Itc interesting to note the amount of food needed 

 by a growing bii'd and then we can judge bettei' as to the 

 number of noxious insei-ts it is able to destroy. Kecall if 

 you please what was said at the outset in regard to the en- 

 ergy with which all the organs of a bird act and it will be 

 more easy to understand what a large anioimt of food is 

 needed to supi)ly the waste necessarily caused by such 

 actiAit\- of the circulator\', respiratorv and othei- func- 

 tions. It seems lU'cdful for the comfort of a l)ird that 

 the stomach should be full nearly all the time. This 

 matter can hardly be moic clearly or accurately presented 

 than by an abstract of a })aper published a few years ago 

 bv Prof. Treadwell of ("ambi'idiic in the Proceeding's of 

 the Boston Society of Natural IIistory(Vol. (5, ]). 31H)). 

 Two (piite young birds wei'c taken which were fed at tirst 

 three worms daily. The number was inci'cased the next 

 da\' and on the third dav eiiiht were ii'iven each in the 

 forenoon and in course of the day one died ;ind on exami- 

 nation, its stomach was found to be empty. The othe]* 

 bird still strong, was given a largei' allowance Avhich was 

 increased to thirty-one worms on the seventh day. From 

 this time the bird and its food were Aveiglied daily. It 

 Avas found in this way that not until the fourteenth day 

 when sixtv-eiii'ht worms, or thirtv-four d^vts. Avere given 

 the bird that it Ijeiran to <»:aiu in Aveiuht. At this time 

 the bird Aveighed tAventy-four dAvts. so that its daily food 

 Aveighed over forty-one per cent, more than itself. The 

 sixtA'-eiaht Avorms measured al)out fourteen feet. After 



