834 THE POPULAR SCIENCE MONTHLY. 



analogous to it, has been noticed in a large number of rodents.* 

 The well-known note of the chipmunk, from which it has derived 

 its name, is the only one I have heard from it. After studying a 

 colony of red squirrels for some weeks last summer, I came to the 

 conclusion that they have a capacity of vocal expression much 

 greater than is commonly believed. Their usual " barking," or 

 trilling, seems to be the commonest, the most instinctive, and not 

 largely expressive of anything beyond general satisfaction ; but 

 I found that, under excitement, there were many other tones, asso- 

 ciated with great complexity of emotion, which I am not prepared 

 to analyze, but which there can be little doubt the creatures them- 

 selves employ as a means of intercommunication. Under marked 

 excitement, as the result of repeated interferences, I have heard a 

 red squirrel so mingle tones of a musical kind that a stranger, 

 arriving on the spot, would certainly have been deluded into the 

 belief that he was listening to some bird, or rather to an excited 

 pair of birds. The musical character of this combination, together 

 with its continuity and complexity, would perhaps justify the 

 designation " song." One of the writers on musical mice refers to 

 their singing but little in certain instances, except when excited, 

 which is a point of analogy with the chickaree. 



It would appear, therefore, that it is likely that, throughout 

 the order Rodentia, a genuine musical appreciation and executive 

 capacity exists, and in some instances in a very high degree ; and 

 that apart from this there is also considerable ability displayed in 

 the expression of states of emotion, at least, by vocal forms. Mani- 

 festly, the degree to which animals can express their psychic 

 states and especially in vocal forms is a matter of the greatest 

 importance, and I have already elsewhere ("Popular Science 

 Monthly," March, 1887) expressed my conviction that animals 

 have a power of communicating with each other, altogether be- 

 yond what has been generally surmised. The subject is beset 

 with great difficulties, and calls for the closest observations. 



The reviewer, in "The Academy," of Dr. Oliver Lodge's "Modern Ideas of 

 Electricity" emphasizes the promise implied in the present state of scientific 

 research and mathematical investigation that some great step forward is about to 

 be made. "It is because the scientific world," he says, "knows itself to be on 

 the verge of discoveries as to the nature of the ether, more far-reaching possibly 

 than the discovery of the mode of gravitation, that it lives in a state of suppressed 

 excitement, which hinders it sometimes from further progress or from recognition 

 of the relative importance of recent work " ; and lie hints that the century wbich 

 produced Darwin is now ripe for almost a greater genius than he. A similar tone 

 is sounded in Prof. Lodge's book. 



* See especially " Nature," vol. xv, " Popular Science Monthly," vol. i, and " The Ameri- 

 can Naturalist." 



