May .2, 1H93.] 



SCIENCE. 



263 



As for the imagination, what is it but a faculty operating under 

 laws as rigid as those of physios ? As the distinguished ethno- 

 grapher, Von Helhvald, remarks: " In spite of the endless mul- 

 tiplicity of forms, yet often one and the same or very nearly 

 allied forms recur in localities widely asunder, and this seems to 

 occur most frequently in forms which are peculiarly strange and 

 artificial. We are almost forced to accept the discouraging sug- 

 gestion of Peschel, that the human faculty of thought is a mere 

 mechanism, which under a given stimulus is always forced to 

 perform the same motion." 



LETTERS TO THE EDITOR. 



^*(i Correspondents are requested to be as brief as possible. The writer's name 

 ia in all cases required as proof of good faith. 



On request in advance, one hundred copies of the number containing his 

 communication loill be furnished free to any correspondent. 



The editor will be glad to publish any queries consonant loith the character 

 of the journal. 



A Physiological Effect of Cave Visiting. 



Dr. Hovey's interesting account of a visit to the Mammoth 

 Cave in IMarch, published in Science for April 7, 1893, recalled a 

 recent conversation with my father, Dr. C. Fayette Taylor, on 

 the subject of the cave, which he visited in July, 1860. He was 

 particularly struck with, and vividly describes, the physiological 

 effects experienced on emerging from the cave. He made the 

 usual long trip with some fifteen companions, reaching upper 

 air after a stay of about twelve hours under ground. On emerg- 

 ing the sense of smell was intensified to such an extraordinary 

 degree, that most common objects, such as trees, plants, ani- 

 mals, and even people had strong individual odors, mostly un- 

 pleasant; about half the party were strongly nauseated and vom- 

 ited. One tree could easily be distinguished from another by its 

 characteristic odor. This effect lasted about half an hour and 

 then passed off. The guides told him that this was a usual ex- 

 perience. Dr. Hovey alludes to this effect of a sojourn in the 

 cave in a lecture published in the Bulletin of the American Geo- 

 graphical Society, March 81, 1891, in the following words: "By 

 contrast with the pure oxygenated air of the cave, the odors of 

 the outside world, of the trees, grass, weeds, and flowers, are 

 strangely intensifled and for many delicate natures overpower- 

 ing." In a letter dated April 11, 1893, Dr. Hovey says: '■! have 

 always, or generally, been accustomed to rest at the entrance on 

 emerging, for the reason thac neglecting this precaution is apt to 

 be followed by disagreeable consequences. I have know visitors 

 to suffer from nausea and headaches by reason of a too sudden 

 change from the peculiarly pure air of the cave to that of the 

 outside world. The sense of smell is greatly intensified in almost 

 every case." 



I jud^e that this intensification of olfactory perceptions is due 

 to the rarity of olfactory stimuli in the cave; on emergence, 

 in accordance with a physiological law, the perceptive powers 

 for these particular stimuli, having rested, are intensified, so 

 that odors too delicate to make an impression under ordinary 

 circumstances are powerfully felt. By the constant repeti- 

 tion of the ordinary olfactory stimuli this effect passes off, and 

 soon only the stronger odors are registered in consciousness. In 

 other words, consciousness is mainly concerned with the regis- 

 tration of the contrast between the stimulus of the moment and 

 a background of fused and undifferentiated impressions. Ordi- 

 narily, sensations are increased by more intense stimulation, but 

 they may also be increased, as in the illustration just given, by 

 varying the background so as to bring ordinary stimuli into 

 stronger relief. That a similar effect has been intensified by 

 heredity is illustrated by Dr. Hovey's remarks on the auditory 

 sensitiveness of the cave fauna. He says in the lecture already 

 referred to: " The tiny [blind] fish are colorless, having cartilage 

 instead of bones, are viviparous, and are so sensitive that if a 

 grain of sand should'fall on the water they would dart away with 

 rapidity. Blind crawfish are also found here, whitish, semi- 

 transparent, with remarkably long antenuee and more delicate in 



every way than those found in outside streams. These also are 

 highly sensitive and not easily captured." 



This agrees with an observation of Professor Cope, quoted in 

 the "Standard Natural History," Vol. III., p. 178. He says the 

 Amblyopses, when swimming near the surface, as is their habit, 

 are "easily taken by the hand or net, if perfect silence be pre- 

 served, for they are unconscious of the presence of an enemv, 

 except through the sense of hearing. This sense is, however, 

 evidently very acute, for, at any noise, they turn suddenly down- 

 ward and hide beneath stones, etc., at the bottom." 



Henry Ling Taylor, M.D. 



New York. 



Pre-Historic Remains in America. 



If Professor Thomas, in Science, May 5, had really desired to 

 inform readers what my conclusion was in reference to the original 

 home of the Mexican or Uto-Aztecan stock, he would have quoted, 

 not various fragments from earlier studies, but the following from 

 "The American Race," p. 131: "That very careful student, Mr. 

 George Gibbs, from a review of all the indications, reached the 

 conclusion that the whole group came originally from the east of 

 the Rocky Mountain chain, and that the home of its ancestral 

 horde was somewhere between these mountains and the Great 

 Lakes. This is an opinion I have also reached from an indepen- 

 dent study of the subject, and I believe it is as near as we can get 

 to the birthplace of this important stock." 



What 1 said of the Mayas was: " The uniform assertion of their 

 legends is that the ancestors of the stock came from a more 

 northern latitude, following doum the shore of the Oulf of Mex- 

 ico." 



If Professor Thomas can controvert either of these propositions, 

 I shall be glad to change my views to his. 



As for his assertion that I "ought to know '" that the shells and 

 copper ornaments found in Tennessee and Georgia "are looked 

 upon by all archcfiologists as puzzling objects because of their re- 

 markable departure from the types of the Atlantic slope," I cer- 

 tainly know nothing of the kind, nor does Professor Thomas. 

 Only last summer that most competent archaeologist. Dr. E. Seler, 

 published an article to show that these very objects are so little 

 of a departure from historic Atlantic types that the theory of a 

 relationship to Maya art is in his opinion unnecessary (see Science, 

 Nov. 4, 1892). 



If Professor Thomas had made himself acquainted with the 

 current literature of American archceology, he would not ha\e 

 risked such a statement. D. G. Brinton. 



Philadelphia, May 8. 



Tornadoes. 



About five o'clock of the evening of April 24, a peculiar wavy 

 appearance was noticed in the clouds, which were moving north. 

 Every few minutes one or more miniature tornadoes would ap- 

 pear. The little funnels would last twenty or thirty seconds, 

 others formed only to be destroyed shortly afterwards. 



The whole time was about fifteen minutes, when the upper 

 layers of clouds became more or less mingled with the lower 

 layers. The barometer had been falling all day. The same 

 eveniug there were two destructive tornadoes in Missouri and a 

 heavy wind-storm at Paxton, Ind. E. M. Danglade. 



Vevay, Ind., April 29. 



Pivotal Sounds in Recollection. 



In 1884 I published the statement that in the endeavor to recall 

 some forgotten word or name that a remarkable tendency existed 

 to substitute another word or name having, somewhere in its con- 

 struction, a letter corresponding to one in the desired word or 

 name. For example, Cavendish suggests itself, or rather may do 

 so, when one is trying to recollect Van Antwerp, and so on; the 

 V being the pivot upon which both names revolve, apparently, in 

 the memory. In addition to this I find, at least in my own ex- 

 perience, an inclination to swing these memory efforts around the 

 R sound more frequently than with other instances; for example, 



