Apeil 10, 1896.] 



SCIENCE. 



563 



slightly; and the occasional small electrostatic 

 spark from the surface of the tube to the hair, 

 but which was hardly noticeable, will also not 

 account for this effect. John Daniel. 



Physical Laboeatoey, 



Vandeebilt Univeesity, March 23, 1896. 



INSTINCT. 



To THE Editor of Science : Having read 

 with considerable interest the discussions under 

 Instinct, and having noticed the different opin- 

 ions expressed concerning the eating and drink- 

 ing of the chick, I thought that perhaps my 

 personal experiments in regard to the matter 

 might be of interest. 



About eight years ago I was desirous of study- 

 ing the chick before and after hatching, and for 

 this purpose I placed about three hundred eggs 

 in an incubator. I shall confine myself to those 

 that were allowed to hatch. 



Those that hatched were divided into two 

 groups, an unhealthy and a healthy group. 

 Those in the first group were fed and given wa- 

 ter until they became strong enough to care for 

 themselves. Those in the second group had 

 food and water placed so that they could get 

 them, but they were not fed nor given water, nor 

 were they taught how to secure food and water. 

 No tapping on the dish or on the floor, and no 

 putting of the bill in the food or water was prac- 

 ticed. They were left entirely to themselves. 



By watching these chicks, I noticed that they 

 would occasionally run over their food and wa- 

 ter, and frequently they stumbled in them. If 

 the beak became wet, up would go the head, 

 and the water was swallowed. If food adhered 

 to the beak, some would get on the tongue, and 

 it would be swallowed. In time they seemed 

 to recognize that the food and water were pal- 

 atable by repeatedly stumbling in them and get- 

 ting them on the beak, aud finally they learned 

 how to secure them, i. e., how to pick them up. 

 I noticed that at first they did not know how to 

 pick up, but, after repeatedly trying, they 

 learned how. The majority of these chicks 

 lived and developed. 



Now if we consider the attempt to pick up, 

 from observation I conclude that it was by in- 

 stinct ; but if we consider the picking up, I con- 

 clude that it was an acquired characteristic. 



In conclusion, I might say that at the end of 

 the third day all of the chicks — about fifty — in- 

 stinctively attempted to pick up, and that at 

 the end of the fifth day they were able to pick 

 up and place the food or water so that it could 

 be swallowed. J. C. Hartzell, Jr. 



' Oeangbbueg, S. C, March 25, 1896. 



visualization and retinal image. 



A STOEY which has been going the rounds of 

 the press about a successful attempt by Mr. 

 Engles Rogers at photographing his own retinal 

 image of a dead child, said image being pro- 

 duced by visualizing effort, induces me to sug- 

 gest through Science that the subject is worthy 

 of more thorough investigation than it has yet 

 received. What effect also hallucination has 

 upon the retina might be determined from study 

 of insane patients dead from hallucinatory 

 fright, etc. In some cases of sudden death by 

 accident there seems to be evidence of a per- 

 sistence of retinal image ; and it seems highly 

 desirable that hospital svirgeons should have a 

 simple instrument for investigating such cases. 

 An image which should represent other scenes 

 than the surroundings at time of death might 

 be evidence for mere visualization effecting a 

 retinal image. Hieam M. Stanley. 



Lake Forest, III. 



naval erosion. 



To the Editor of Science : An interesting 

 locality for obtaining some measure of the inter- 

 ference of navigation with the normal geological 

 cycle is the Kennebec River, in Maine. Several 

 summers ago, chancing upon this river, I was 

 struck with the completeness of the phenomena 

 of erosion produced by our steamer in disturb- 

 ing the water. 



This stream is an estuary for nearly forty 

 miles from its mouth. It has numerous islands 

 and in many places steep banks. There is a 

 vast amount of glacial material strewn along its 

 shore which, with the matter brought down 

 stream, has silted the river bottom completely. 

 I noted all along the shore that the water in 

 advance of the steamer rose slightly on the 

 bank, but was immediately drawn back to fill 

 the space just occupied by the boat. At some 

 points this recession amounted to fifteen or 

 twenty feet, and at no place was it less than 



