186 CRIES. 



this way, is uncommonly harsh and disagreeable, and 

 not very intense. 



Emily. You say these birds with convoluted tracheae 

 have not intense voices, but the crane and swan are large 

 birds, and we should think they would have intense 

 voices. 



Dr. B. It is found by observation that the intensity 

 of the voice in birds, depends on the strength of the 

 muscles connected with the vocal organs, and it is not 

 true that the strength of these mucles is always propor- 

 tioned to the size of the bird. 



It has been found by Mr. Hunter, that in singing-birds, 

 the loudest songsters have the strongest muscles connec- 

 ted with their vocal organs. The English lark whose 

 voice is so intense that it may be heard after he has risen 

 in the sky out of sight, has the most powerful muscles 

 of all the singing-birds. 



Emily. As Shelly beautifully speaks of it 



Like a star of heaven 



In the broad day-light, 

 Thou art unseen, but yet I hear thy shrill delight. 



Dr. B. The organs of voice in reptiles are much less 

 complicated in their construction than in all other animals, 

 and hence their voice consists of a mere croaking, his- 

 sing sound. In the adder, viper, and the serpents in 

 general, we find only a glottis, and of course, the voice 

 is imperfect in proportion to the imperfection of the or- 

 gan. Serpents are not known to utter any other sounds, 

 than mere hisses, and those only when enraged. The 

 tortoises seem to be unable to utter any sound whatever. 



Emily. The frogs have no reason to complain that 

 nature has not endowed them with vocal powers of no 

 contemptible strength and volume. 



Dr. B. Having now spoken of those " various in- 

 struments with which, animals, each playing his part, 

 perform the great concert of nature," we shall speak 

 more particularly, to continue the figure, of the music it- 

 -elf. Man like other animals, is capable of uttering 



