SCIENTIFIC ED UCA TION. 417 



Thus two lips form the vocal cords, which are stretched or relaxed by a 

 very complicated action of the muscles. This accounts for the immense 

 variety of sounds among birds, replying to the diversity in the structure of 

 the larynx. 



The greater number of small birds have cries of joy or fear, appeals for 

 help, cries of war. All these explosions of voice borrow the sounds of vow- 

 els and consonants, and show how easy and natural is articulation among 

 them. Tiiose species which are distinguished as song-birds have a very 

 <;omplicated vocal apparatus. For the quality of tone, power, brilliancy, 

 and sweetnes, the nightingale stands unrivaled; yet it does not acquire this 

 talent without long practice, the young ones being generally mediocre. The 

 parrots which live in large numbers under the brightest suns, have a love 

 for chattering which captivity does not lessen. Attentive to every voice 

 and noise, they imitate them with extraordinary facility; and the phenom- 

 enon of their articulating words is still unexplained. It is supposed that 

 there is a peculiar activity in the upper larynx. As a rule, they attach no 

 meaning to what they say ; but there are exceptions. When very intelli- 

 gent and well instructed, these birds — such as M. Truefitt's late parrot, an 

 account of which appeared in Vai^ Journal in 1874 — can give a suitable an- 

 swer to certain questions. 



Our notes on this interesting study come to a close. Man is well served 

 by his voice; words are the necessity of every-day life; singing is its plea- 

 ure and recreation, whether the performers are human beings or birds — 

 Chamber's Journal. 



SCIENTIFIC EDUCATION. 



COMMENCEMENT ADDRESS, BY ALFRED P. BOLLER, C E., 



To Graduating Class of 77 at Rensselaer Polytechnic Institute. 



Once more, in the sequence of events, the season of the year has arrived 

 when the higher educational institutions throughout the land are all aglow 

 with the excitement of "commencement day," while fathers and mothers 

 await the hour, with proud satisaction, when the coveted parchment, certi- 

 fying to all manner of learning, will have been formally bestowed upon their 

 representatives in the rising generation. Thenceforth, the dij)loma becomes 

 a family heirloom, to be carefully stowed away in its japanned tin case among 

 the family archives, or perchance hung upon the wall of the family sitting- 

 room in a handsome frame, a daily reminder of what "our boy" has accom- 

 plished. Amid all the changes that have taken place in our educational 

 systems, the practice of a public introduction to the world, of the completed 

 product of such schools as confer degrees, is one that even the most radical 



