Ol-TOBKIt S. 



I'JOS.] 



SCIENCE. 



5H7 



the same reasons, and also because the 

 macula has no capillaries. 



In other words, the movements are not 

 oeular in origin, unless in a last anal.vsis they 

 are due to a shifting of the functional ac- 

 tivity from one set of macular cones to an- 

 other. The direction of the movements with 

 a single eye seems to forbid this supposition, 

 and one is driven to think of them as caused 

 by the mechanism or physiology of the sen- 

 sation-making centers in the cuneus of the 

 occipital lobe — the cerebral center for vision. 

 The fact suggests several not uninteresting 

 queries as to the psychology and pliysiolog.v 

 of sensation. 



The practical bearings of the phenomenon 

 are of far greater importance and interest, 

 and ma.v be vaguely indicated as follows: 

 There is no doubt, of course, as to the fact 

 of the subjective production of images, ghosts, 

 wraiths, telepathic visions, , animals, snakes, 

 etc., in delirium tremens, in clairvoyant 

 states, in hypnotic conditions, in pathologic 

 conditions of the mind and body and even in 

 some people in health, when the mind is in 

 a state of heightened sensibility, etc. It will 

 be remembered that the vast majority of these 

 subjective sensations occur in the night, iii 

 dim light, etc. If they occur with the eyes 

 closed, that does not change the essential psy- 

 chologic law of the apparent action and move- 

 ment of the image, which must be conditioned 

 upon the physiology or mechanics of visual- 

 ization. The apparent movements of the im- 

 ages will obey the same laws of seeing, shift- 

 ing as those of the distant light in the night. 

 The facts of crystal-gazing, apart from the 

 mere subjective creation of the images (about 

 which, I take it, there is no doubt in the 

 minds of students) and especially of the 

 movements of those images, may receive a 

 psychologic explanation, at least some light 

 and rationality, from the analogy of the move- 

 ments of the light I have described. 



Geo. M. Gould. 



I'niLADEI.PHIA, 



September 27. 1!)03. 



SHORTER .\RllCLi:s. 

 BACTEKUL SPOT, A NEW DISEASE OF CAKNATIOX.S. 



We have recently received for examination 

 from Pennsylvania and the District of Co- 

 lumbia a number of carnation plants suffering 

 from a spot disease of the leaves and stems 

 that appears to be quite distinct from anything 

 hitherto described. In its earlier stages the 

 disease looks something like stigmonose, or 

 puncture disease, but the small spots are 

 usuall.v surrounded by a narrow, water-soaked 

 area or ring, while the center of the spot is 

 usually slightly brown. As the spots grow 

 larger they resemble more the ordinary car- 

 nation spot caused by Seploria dianthi. The 

 water-soaked marginal area, however, makes 

 it eas.v to distinguish from this latter disease. 

 The spots increase in size more rapidl.v in 

 soft-leaved varieties and soon collapse and dry, 

 leaving a brown, sunken area. Badly diseased 

 leaves soon withei-. Microscopical examina- 

 tion shows that the spots in all stages arc 

 filled with bacteria, which, in the early anil 

 middle stages of the disease, are usually in 

 pure cultures. These bacteria grow rapidly 

 in beef broth and nutrient agar (acidity plus 

 15 of Fuller's scale) and on ten per cent, 

 nutrient gelatine of the same acidity, but 

 where malic acid is added to the nutrient gela- 

 tine at the rate of one half gram per' one 

 hundred cubic centimeters, the growth is ex- 

 tremely slow. The germ also grows well upon 

 steamed potato. The colonies are round and 

 uiibranchcd, i)carly white, wet and shining, 

 and do not spread rapidly over the culture 

 medium. After a few days the central por- 

 tions of the colonies break up into zoogloea. 

 The complete cultural characters for various 

 media have not yet been determined, but are 

 now being investigated. It is evident that the 

 organism causing this disease is quite dis- 

 tinct from the orange-colored one. Bacterium 

 (lianllii. described by Arthur and BoUe.v as 

 the cause of ' Bacteriosis ' of carnations. In- 

 oculation experiments have been made, both 

 from a maceration of young diseased spots in 

 distilled water and from pure cultures in beef 

 bouillon. Bacteria from both sources, when 

 applied to the surface of loaves, old or young. 



