PHYSIOLOGY. 



691 



and Pilliet examined the tongues of a large 

 number of mammals with special reference to 

 the presence or absence of the papillae foliata?. 

 They found them existing in marsupials, 

 edentates, insectivora, rodents, proboscidje, and 

 swine; and wanting in cetacea, chiroptera, 

 perissodactyla. ruminantia, and many carniv- 

 ora. Frederick Tuckerman observes that there 

 are probably many groups of existing animals 

 whose remote ancestur>]M><.-e<sed foliate areas, 

 which have long since disappeared from their 

 present representatives. An exception is met 

 in the swine, which have undergone fewer 

 structural modifications from the primitive 

 type than most of the other mammals since 

 the Eocene period. According to this author, 

 this organ in the pig is now and then rudi- 

 mentary, is usually more or less atrophied, 

 and very frequently shows a want of symmetry 

 between the two papilla?. "With a single ex- 

 ception all the specimens of swine's tongues 

 examined had well-developed foliate areas. The 

 papilla foliata consists of four or five rather 

 irregular folds, with slightly rounded crests, 

 separated by furrows varying much in breadth, 

 and slightly in depth. Occasionally the bot- 

 tom of a furrow is invaginated upward into a 

 ridge, which may or may not bear taste-bulbs. 

 Serous glands and ducts are very abundant 

 at the base of the folds and occupy a large 

 space within them. Some of the ducts of 

 these glands are very tortuous, and several 

 millimetres in length. They usually open be- 

 tween the folds at the bottom of the fur- 

 Glands of the mucous type are spar- 

 ingly scattered through this region. Each fold 

 carries at its upper part many secondary papil- 

 la?, the depressions between which are filled 

 by the epithelium. The taste-bulbs of this 

 gustatory region are a little smaller on the 

 average than those of the circumvallate area, 

 and are estimated to number 2.400 for each 

 papilla. Dr. Tuckerman quotes from Dr. 

 Luigi Gritfini, of Modena, on his experimental 

 study of the reproduction of the gustatory 

 papillfe and regeneration of the taste-bulbs in 

 the rabbit and dog. Destruction, partial or 

 complete, of the organs of taste appears to be 

 effected by the direct removal from the animal 

 of tlie papillae themselves, or by division of 

 the glosso-pharyngeal nerves. The process of 

 reproduction is described in the memoir. Grif- 

 fini rejects the theory of direct continuity be- 

 tween nerve-fibers and epithelial cells, and 

 asserts that reproduction of the papilhe after 

 their partial or complete removal always takes 

 place. He has also made an experimental 

 study of the organ of smell, the motorial end- 

 plate of the muscle-fiber, and the retina of the 

 lower animals, the results of which have not 

 been published. Dr. Tuckerman has added to 

 his contributions in this branch studies of the 

 tongue and gustatory organs of Fiber Zibe- 

 theeus, and of the gustatory organs of Putorlus 

 Vixon. 

 In the experiments of E. H. S. Bailey and E. 



L. Xichols upon the delicacy of the sense of 

 taste as to different classes of substances, qui- 

 nine, cane-sugar, sulphuric acid, sodium bicar- 

 bonate, and common salt were employed as 

 severally representing, typically, the bitter, 

 sweet, acid, alkaline, and" saline tastes. The 

 A- ere made upon 82 men and 46 women. 

 The average results were as follow : 



I. Quinine: 



Male observers detected 1 part in 390.000 parts of water. 

 Female observers detected 1 part in 456,000 parts of water. 



II. Cane-sugar : 



Male observers detected 1 part in 199 parts of water. 

 Female observers detected 1 part in '204 parts of water. 



III. Sulphuric acid : 



Male observers detected 1 part in 2.0SO parts of water. 

 Female observers detected 1 part in 8,250 parts of water. 



IV. Bicarbonate of soda : 



Male observers detected 1 part in 95 parts of water. 

 Female observers detected 1 part in 12o parts of water. 



V. Common salt : 



Male observers detected 1 part in 2.2-10 parts of water. 

 Female observers detected 1 part in l,9sO parts of water. 



The authors conclude that the sense of taste- 

 is much more delicate for bitter substances than 

 for the others included in the list (the relative 

 delicacy for quinine and sugar being very nearlv 

 : 1); that, taken in the order of their ef- 

 fect upon the organs of taste, the classes of 

 substances must stand in the order bitters, 

 acids, saline substances, sweets, and alkalies ; 

 that the sense of taste is, as a rule, more deli- 

 cate in women than in men (in the case of all 

 the substances tried excepting salt) ; that the 

 ability to detect a dilute bitter is very gener- 

 ally accompanied by inability to detect a dilute 

 sweet, and vice versa ; and that the long-con- 

 tinued habitual use of a substance does not 

 seem to influence in any marked way the deli- 

 cacy of the sense of taste for that substance. 

 "While these conclusions represent the average 

 results, the tests brought out some astonishing 

 individual peculiarities. Thus there were per- 

 sons who could detect with certainty 1 part of 

 quinine in 5.120,000, while others failed to 

 notice 1 part in 160,000. 



A device for measuring the acuteness of the 

 sense of smell has been invented by M. Zwaar- 

 demaker, of Utrecht. It consists of two tubes, 

 a smaller one of glass and a larger one of In- 

 dia-rubber or gutta-percha, sliding over the 

 former in such a way that tha air breathed in 

 by the nostrils at the free end of the glass tube 

 may pass through a desired length short or 

 locg of the odor-beanng tube. The length 

 is read off in centimetres, which it is required 

 to give to the passage in the odor-bearing tube 

 to produce a definite olfactory impression upon 

 the nose. 



Circulation. The changes in the volume of the 

 heart and the amount of blood propelled by it 

 under varying conditions of pressure have been 

 studied by Prof. Roy and J. G. Adami. A 

 slight compression of the abdomen of a dog 

 caused an increase in the volume of the heart 

 and in the amount of blood passing through it 

 in a given time. The phenomenon is explained 

 by the fact that the abdominal vessels are capa- 

 ble of containing more than all the blood in the 



