311 



SCIENTIFIC SIDE-LIGHTS 



Horse 

 Hunting 



was adopted in 1848; and tho their primary 

 effect is only to abolish pain, they get rid of 

 so much nervous irritation as greatly to aid 

 in the subsequent recovery. The use of 

 anesthetics thus renders it possible for 

 many operations to be safely performed 

 which, without it, would endanger life by 

 mere shock to the system; while to the 

 operating surgeon it gives confidence, and 

 enables him to work more deliberately and 

 carefully, from the knowledge that the 

 longer time occupied will not increase the 

 suffering of the patient or render his recov- 

 ery less probable. WALLACE The Wonderful 

 Century, ch. 14, p. 147. (D. M. & Co., 1899.) 



1517. HUMMING-BIRDS, HYBRIDISM 

 NOT FOUND AMONG Numerous Species 

 Keep Distinct. We have the emphatic 

 declaration of Mr. Gould that among the 

 thousands of specimens which have passed 

 through his hands, from all the genera of 

 this great family, he has never seen one case 

 of mixture or hybridism between any two 

 species, however nearly allied. But this 

 passage is so important that I quote it en- 

 tire : " It might be thought by some per- 

 sons that four hundred species of birds so 

 diminutive in size, and of one family, could 

 scarcely be distinguished from each other; 

 but any one who studies the subject will 

 soon perceive that such is not the case. 

 Even the females, which assimilate more 

 closely to each other than the males, can 

 be separated with perfect certainty; nay, 

 even a tail-feather will be sufficient for a 

 person well versed in the subject to say to 

 what genus and species the bird from which 

 it has been taken belongs. I mention this 

 fact to show that what we designate a 

 species has really distinctive and constant 

 characters; and in the whole of my experi- 

 ence, with many thousands of humming- 

 birds passing through my hands, I have 

 never observed an instance of any variation 

 which would lead me to suppose that it was 

 the result of a union of two species. I 

 write this without bias one way or the 

 other as to the question of the origin of 

 species. I am desirous of representing Na- 

 ture in her wonderful ways as she presents 

 herself to my attention at the close of my 

 work, after a period of twelve years of in- 

 cessant labor, and not less than twenty 

 years of interesting study." ARGYLL Reign 

 of Law, ch. 5, p. 141. (Burt.) 



1518. HUMMING-BIRDS IN SNOW- 

 STORM Insect Food of Flower-loving Birds. 

 Two species of humming-birds are com- 

 mon. Trochilus forficatus is found over a 

 space of 2,500 miles on the west coast, from 

 the hot, dry country of Lima to the forests 

 of Terra del Fuego where it may be seen 

 flitting about in snow-storms. In the wooded 

 island of Chiloe, which has an extremely 

 humid climate, this little bird, skipping 

 from side to side amidst the dripping foli- 

 age, is perhaps more abundant than almost 

 any other kind. I opened the stomachs of 



several specimens, shot in different parts of 

 the continent, and in all remains of insects 

 were as numerous as in the stomach of a 

 creeper. When this species migrates in the 

 summer southward, it is replaced by the 

 arrival of another species coming from the 

 north. This second kind (Trochilus gigas) 

 is a very large bird for the delicate family 

 to which it belongs; when on the wing its 

 appearance is singular. Like others of the 

 genus, it moves from plae to place with a 

 rapidity which may be compared to that of 

 Syrphus amongst flies, and Sphinx among 

 moths ; but whilst hovering over a flower, it 

 flaps its wings with a very slow and power- 

 ful movement, totally different from that 

 vibratory one common to most of the 

 species, which produces the humming noise. 

 I never saw any other bird where the force 

 of its wings appeared (as in a butterfly) so 

 powerful in proportion to the weight of its 

 body. When hovering by a flower its tail 

 is constantly expanded and shut like a fan, 

 the body being kept in a nearly vertical 

 position. This action appears to steady and 

 support the bird, between the slow move- 

 ments of its wings. Altho flying from 

 flower to flower in search of food, its stom- 

 ach generally contained abundant remains 

 of insects, which I suspect are much more 

 the object of its search than honey. The 

 note of this species, like that of nearly the 

 whole family, is extremely shrill. DARWIN 

 Naturalist's Voyage around the World, ch. 

 12, p. 271. (A., 1893.) 



1519. HUNTING, A NATURAL IM- 

 PULSE Inherited Tendencies to Cruelty 

 Resolute Endeavor Needed to Overcome. 

 The hunting instinct has a remote origin In 

 the evolution of the race. The hunting and 

 the fighting instinct combine in many mani- 

 festations. They both support the emotion 

 of anger; they combine in the fascination 

 which stories of atrocity have for most 

 minds; and the utterly blind excitement of 

 giving the rein to our fury when 'our blood 

 is up (an excitement whose intensity is 

 greater than that of any other human pas- 

 sion save one) is only explicable as an im- 

 pulse aboriginal in character, and having 

 more to do with immediate and overwhelm- 

 ing tendencies to muscular discharge than 

 to any possible reminiscences of effects of 

 experience or association of ideas. I say 

 this here because the pleasure of disinter- 

 ested cruelty has been thought a paradox, 

 and writers have sought to show that it is 

 no primitive attribute of our nature, but 

 rather a resultant of the subtile combina- 

 tion of other less malignant elements of 

 mind. This is a hopeless task. If evolution 

 and the survival of the fittest be true at all, 

 the destruction of prey and of human rivals 

 must have been among the most important 

 of man's primitive functions, the fighting 

 and the chasing instincts must have become 

 ingrained. . . . It is just because hu- 

 man bloodthirstiness is such a primitive 



