October 14, 1892.] 



SCIENCE. 



15 



in later life. This method of defence would not be so effectual 

 upon the surface of the ground where its enemy could attack it 

 from any source instead of directly behind or before, because 

 with its unwieldy body it would not be able to eject the substance 

 In any desired direction suddenly. This, then, appears to be a 

 habit acquired by the insect since it has taken to its underground 

 life; for it is hardly probable that it would be provided both with 

 the habit of making long leaps to escape from its enemies, and 

 at the same time to eject in large quantities this protective fluid. 



There are some rather serious objections to this theory of 

 changed conditions and habits. First may be mentioned the 

 unusual development of the tarsus, fitting it for its underground 

 life and burrowing propensities ; but it is not unreasonable to 

 suppo.^e that the front legs were developed gradually in confor- 

 mity with its changing habits. And it is perhaps true that if the 

 insect lived upon the ground, it occasionally burrowed for roots, 

 or for shelter, and originally had an unusual development of the 

 tarsus. Its carnivorous habits may have been acquired in conse- 

 sequence of its frequent contact with earth-worms, when other 

 food was scarce, as there are many other insects which normally 

 feed upon vegetable food, that will resort to animal food, devour- 

 ing even their own kind, as in the mole cricket, when pressed by 

 hunger. 



Second, an observation made by Westwood and others in 

 Europe upon O. vulgaris would seem to weaken my argument 

 regarding the development of the insect. It is stated that the 

 larvae of the European species, before the first moult, live 

 together in one burrow, with the mother cricket, but scatter after 

 this moult. I have seen the very young larvae of our species only 

 in confinement, and cannot say whether in the natural state they 

 would scatter before this time or not. They run about in the 

 breeding-cage more before the first moult than afterward. How- 

 ever, I think it probable that the mother cricket feeds the young, 

 at this early stage, as she exercises great solicitude for them ap- 

 parently, in other matters, or in time of danger. I have several 

 times seen the mother take the young in her mouth when dis- 

 turbed, as a cat does her kitten, and carry them to places of 

 safety. She will also carry her eggs to a new burrow when they 

 have been discovered, as I have several times observed. Hence 

 it seems probable the young larvse live together under the protec- 

 tion of the mother cricket, and would have but little need of a 

 protective ejection. But the jumping habit which is chiefly use- 

 ful in escaping from their enemies, being confined only to the 

 early larval stage, presents a stronger argument for changed con- 

 ditions. I may say, however, that neither of these are presented 

 as conclusive arguments but rather mere suppositions or sugges- 

 tions, to be followed up by other observations. 



THE SCIENCE OF S.VIELLL^G. 



BT PEOF. DE VOLSON WOOD, STEVENS INSTITUTE, HOBOKEN, N. J. 



The greater part of the science of seeing is contained in the 

 science of optics, and this is founded upon the theory of undula- 

 tions of the ether and the way in which they are modified by the 

 media through which they pass. The form of the surface, 

 whether plane or curved, as well as the density of the medium 

 produces marked effects. 



Similarly, the greater part of the science of hearing is con- 

 tained in the science of acoustics, and this also treats of undula- 

 tions, or waves propagated in air or other gases. It is not believed 

 in either case that solid particles pass from a source to the sensi- 

 tive nerves to produce the particular sensation. 



Why should there not be a science of smelling ? The principal 

 part of such a science would consist of an investigation of the 

 mechanic.il proiserties of odors, and might briefly be called 

 " Odorology." Is it not highly probable that odors are also propa- 

 gated by undulations of an ether? And yet we are familiar with 

 the statements made by writers, such as " A grain of musk will 

 keep a room scented for many years. During the whole of the 

 time it must be slowly evaporating, giving out its particles to the 

 currents of air to be wafted presently out of doors ; yet in all this 

 time the musk seems to lose but little of its weight." "The 

 acute sense of smell of the dog is well known ; for he can detect 



the track of his master long after the tracks have been made, 

 which shows that some slight characteristic matter is left at each 

 footfall." 



Those who thus speak impart the idea that odor is material. I 

 prefer to think of it as a property of matter, which produces its own 

 peculiar undulations; and that the sensation of odor is produced 

 by these undulations in the olfactories. IMusk retains this prop- 

 erty for a very long time, while some bodies lose it rapidly. The 

 man may leave some characteristic matter on the ground at each 

 footstep, but it is not necessary that particles of that matter shall 

 pass from the ground into the nose of the dog in order that he 

 may track his master. It is only necessary that that matter shall 

 possess the property of .sending forth certain undulations. In- 

 deed, it is not difficult to conceive that the ground itself has im- 

 parted to it the property of sending forth the desired undula- 

 tions. 



These facts being assumed, investigations might be made to 

 determine the velocity with which odors are propagated, and 

 whether they are subject to reflection, refraction, and interfer- 

 ence, and other properties common to sound and light; also 

 whether the different odors are due to different wave-lengths, and 

 if the strength and intensity of the odor is due to the amplitude 

 of the wave, as in light and sound. The physiological qualities 

 of the olfactories by which they enable one to detect odors of dif- 

 ferent qualities and intensities furnish a field for the most deli- 

 cate and refined investigation.' 



NOTES AND NEWS. 



Persons who are very susceptible to the effects of gnat-bites 

 state that the irritation seems to return on the third day, and in 

 those who have exceptionally sensitive skins again on the sixth 

 day. Thus the effects of gnat-bites, or rather of the poison which 

 they instil into our blood, have a certain analogy with the .symptoms 

 of intermitrent fever. This need, perhaps, scarcely surprise us if 

 we recollect from what materials the juices of the gnat have been 

 elaborated. 



— Herbert M. Thompson's "The Theory of Wages and its Ap- 

 plication to the Eight-Hours Question," published by Macmillan 

 & Co.. is a timely contribution to the discussion of this vital ques- 

 tion of the present industrial crisis. 



— Lovers of birds and flowers will delight in Miss Yonge"s new 

 book announced by Macmillan & Co. Under the title of "An Old 

 Woman's Outlook " she describes out-door life in England as she 

 has watched it for so many years. The chapters are so arranged 

 that each shall cover its special month. 



— "Round London, Down- East, and Up-West" is the self-ex- 

 plaining title of a new book by Montagu Williams, barrister, author 

 of "Leaves From a Life," etc. It will be issued by the Macmil- 

 lans. 



— D. Appleton & Co. will shortly add to their list of Good 

 Books for Young Eeaders " Along the Florida Reef," by C. F. 

 Holder, which is a story of camping and fishing adventures in 

 company with a naturalist in Florida. The author combines en- 

 tertainment and instruction, and his book is filled with illustra- 

 tions which will be prized by every young reader who has ever 

 visited the seashore, or cares for information regarding fishes, 

 shells, and the various forms of marine life. The same firm will 

 publish immediately "The Story of Columbus,'' by Elizabeth 

 Eggleston Seelye, edited by Dr. Edward Eggleston. with nearly a 

 hundred illustrations by Allegra Eggleston. This book is the re- 

 sult of extensive investigations which have been carefully verified 

 by Dr. Eggleston. While the book contains all the results of 

 modem inquiry offered in the bulkiest biographies, the story is 

 here condensed and the material selected with a view to an 

 always interesting narrative. To a considerable extent the plan 

 of both text and illustrations is like that of Eggleston's " House- 

 hold History of the United States." "The Story of Columbus" 

 will be the first volume in a series to be called Delights of His- 

 tory, which will be prepared by the same author, artist, and 

 editor. 



