PHYSIOLOGY. 



661 



but in either case the action is hesitant; for 

 during a period after excitation, which amounts 

 at ordinary summer temperature to about a 

 second, the leaf remains absolutely motionless, 

 and during this interval an electrical disturb- 

 ance takes place in the plant. Differences, 

 obvious and well marked, exist between the 

 mechanism of plant-motion and that of animal 

 motion ; but they are not essential, for they 

 depend, not on difference of quality between 

 the fundamental chemical processes of plant 

 and animal protoplasm, but merely on differ- 

 ences of rate or intensity. 



Localization of Function. In a paper on the 

 effects of lesions of different regions of the 

 cerebral hemispheres, read before the Royal 

 Society, Drs. Ferrier and Gerald Yeo give a 

 detailed account of experiments conducted 

 upon monkeys, consisting in the removal un- 

 der anaesthetics of certain limited areas of the 

 cortex. The regions operated upon were the 

 occipito-angular, temporal, Rolandic, frontal, 

 and hippocampal. It was found that lesions 

 of the occipital lobes and angular gyri caused 

 disturbances of vision, of importance varying 

 with the extent of the lesion. Unilateral ex- 

 cision of the occipital lobe and angular gyrus 

 induced temporary amblyopia of the oppo- 

 site eye and homonymous hemianopia of both 

 eyes toward that opposite side. Experiments 

 on the superior temporo-sphenoidal convolu- 

 tion were followed by complete and perma- 

 nent deafness, other lesions of the temporal 

 lobe producing no change in this sense. The 

 Rolandic region or the cortical layers around 

 the fissure of Rolando was again shown to 

 be the center of motor impulses, lesions in 

 those areas producing motor paralysis without 

 loss of sensation, varying in degree and extent 

 according to the seat and extent of the lesion ; 

 secondary degeneration of the pyramidal tracts 

 of the spinal cord followed these lesions. No 

 effects followed lesions of the prefrontal re- 

 gions. Only temporary paralysis of the lateral 

 movements of the head and eyes was produced 

 by lesions of the post-frontal region, temporary 

 so long as portions of the frontal lobes re- 

 mained. Lesions of the frontal lobes were 

 followed by descending degeneration, traced 

 through the center of the foot of the crus cerebri, 

 and of corresponding fibers of the internal cap- 

 sule, but not passing into the anterior pyramids. 

 The result of the removal of the hippocampus 

 major and its convolution and the neighboring 

 inferior temporo - sphenoidal region, without 

 interference with the crus or the basal ganglia 

 or internal capsule, was to cause complete an- 

 aesthesia of the opposite side of the body, the 

 degree of such anaesthesia depending upon the 

 amount of destruction of the hippocampal re- 

 gion. 



Physiology of Aqnatie Life. Experiments made 

 and reported upon by Prof. Sydney Ringer to 

 determine the influence of the saline constitu- 

 ents of fresh water on fishes show that while 

 fish will live for weeks unfed in "tap-water," 



they die, when placed in distilled water, in a few 

 hours, minnows, for instance, in an average of 

 four and a half hours. The addition, however, 

 either of a sodium or a calcium salt in minute 

 proportions greatly prolongs their life. Sodi- 

 um chloride, sodium bicarbonate, and potassi- 

 um chloride, added singly to distilled water, sus- 

 tain life for the same time, namely, from one to 

 two days, sodium bicarbonate prolonging life 

 rather longer than either of the other two salts. 

 Calcium chloride added to distilled water sus- 

 tains life much longer than either correspond- 

 ing quantities of sodium or potassium salts. 

 The addition of sodium carbonate greatly en- 

 hances the life-prolonging power of calcium 

 chloride, the combination, indeed, appearing as 

 capable of sustaining life as " tap-water." Dr. 

 Ringer finds that while a reduction of the rela- 

 tive quantity of salts below a certain point 

 renders water incapable of sustaining life, fish 

 like minnows and sticklebacks can exist in fluids 

 containing a considerable excess of salts over 

 the amount common in river-waters. He finds, 

 too, that by gradually reducing the quantity of 

 sodium salts, he can habituate minnows and 

 sticklebacks to live in a fluid containing only 

 a calcium salt or calcium chloride. Stickle- 

 backs, which are anadromous, become much 

 more readily habituated to a fluid of a different 

 composition from that to which they are accus- 

 tomed, and far more readily, than minnows. In 

 some of his experiments the author noticed 

 that one, two, or more of the minnows greatly 

 outlived the rest. This was not because the 

 fish in question became habituated to the dis- 

 tilled water, for they died speedily when placed 

 in a fresh supply of it; and Dr. Ringer pre- 

 sumes, as a more tenable supposition, confirmed 

 by circumstantial evidence, that the other fish 

 gave up something to the water, probably in- 

 organic salts, which enabled it to sustain life. 

 The general conclusion drawn from the experi- 

 ments is, that, to sustain the life of fish, the 

 water in which they live must contain a mi- 

 nute quantity of various salts, for instance one 

 in from 5,000 to 10,000 parts of calcium and 

 sodium salts ; that in water containing a small- 

 er quantity, fish languish and die, while they 

 die still sooner in distilled water. On the 

 other hand, they can live in a great excess of 

 lime over the minimum essential to sustain 

 life. 



The experiments of Mr. H. A. Coutance on 

 bivalve and univalve mollusks are partly paral- 

 lel with those of Prof. Ringer, and supplement 

 them. By reason of their different organiza- 

 tion, the mollusks experimented upon gave 

 very different results. The bivalves, which 

 could shut themselves up between their valves, 

 as a general rule showed greater resistance 

 than the univalves. Of these, the periwinkles, 

 whose operculum can close entirely, retired 

 into the remotest coils of their spirals, and were 

 thus better protected than the buccins, whose 

 opening does not shut tightly, and into which 

 the water can easily enter. Salts of potash 



