THE HEAVENS IN FEBRUARY 



267 



proximately that shown in Figure 2. 

 But what the physical condition of the 

 cloud is is still largely a matter of con- 

 jecture, though we are certain that its 

 average density must be almost incon- 

 ceivably small. 



One of the most interesting of recent 

 mathematical investigations has shown 

 that if the densest part of this cloud is 

 only so much as one fifty millionth part 

 that of our air, the pull of the mass 

 iipon the inner planets will be just suf- 

 ficient to cause the hitherto unexplain- 

 ed disturbances of their motions. It 

 may be remembered that in order to 

 explain these disturbances the assump- 

 tion was made many years ago that 

 there existed an unseen planet moving 

 inside of the orbit of Mercury, and to 

 this supposed planet there was given 

 the name of Vulcan. It has long been 

 regarded as nearly certain that Vulcan 

 has no existence. Now that it has been 

 shown how the pulls of the exceedingly 

 tenuous mass of the Zodiacal Liqiit 

 upon the inner planets are sufficient 

 to explain their deviations from their 

 predicted courses, the assumption of 

 the existence of unseen bodies in the 

 solar system becomes unnecessary. 



An Open Mouth as an Expression of 

 Intelligence. 



We have previously noticed an in- 

 teresting book, "Wild Animals and 

 the Camera." by W. P. Dando, F. Z. 

 S.. published in London by Jarrold & 

 Sons, and in New York by the Fred- 

 erick A. Stokes Company. 



The photographs are especially good 

 portrayals of the animals of the Lon- 

 don Zoological Garden. Perhaps the 

 most sensational is that of the hippopot- 

 amus. "Guv Fawkes." The author makes 

 the novel suggestion that the wide open- 

 ing of the mouth at the word of com- 

 mand is an indication of intelligence. 1 

 wish one could say the same thing of 

 other forms of life because there are 

 some examples, not unknown to most 

 people, where a too wide, or a too fre- 

 quent or a too vociferous opening of the 

 mouth has not been regarded as an in- 

 dication of the highest intelligence. 

 But should we expect a rule to be of 

 universal application? Perhaps this 

 manner of manifesting intelligence is 

 not more applicable to four-footed ani- 

 mals than to mankind, and no more 



invariably applicable than certain bio- 

 logical principles that certain scien- 

 tists have been persistently telling us 

 are of universal application. The au- 

 thor says : 



"The hippo has never been a great 

 favourite with the public which is prov- 

 ed by the fact that very little of the 



A REMARKABLE EXPRESSION. 



food given to the animals by the visi- 

 tors, which amounts to many tons a 

 year, ever found its way to 'Guy 

 Fawkes,' who, although by nature 

 herbivorous, was as fond as an elephant 

 of a bun, and would open her enormous 

 mouth at the word of command, which 

 to my mind proves she was not so 

 wanting in intelligence as some people 

 would make out." 



Birds and Bird Music. 



Mr. Henry Oldys of Silver Spring, 

 Maryland, a most efficient lecturer on 

 birds and bird music, is to make a 

 tour of New England in the spring 

 of 1913. In the course of his study of 

 bird music, he has discovered many 

 evidences of close relationship between 

 bird music and the human voice. 

 These discoveries have been presented 

 before various scientific societies and 

 in popular magazine articles. We be- 

 speak for him a cordial reception in 

 every place that he may visit in his 

 New England tour. 



