804: 



SCIENCE. 



(Vol. II., No. 4i!, 



on the other hand, from experiments made upon rab- 

 bits, says, that after perforation of the aortic valves, 

 there is an important fall of pressure. De .Tager has re- 

 peated these experiments, using botli dogs and rabbits. 

 Upon dogs he finds that perforation of the valves has 

 little or no effect on arterial pressure; where.as, with 

 rabbits, a considerable and permanent fall of pressure 

 is the result. It appears from these experiments 

 tliat the compensatory power of the lieart-muscle is 

 greater in the dog than in the rabbit, althougli de 

 Jager tiiinlcs that the results may be partly explained 

 by tlie fact that the injury to the valves in the case 

 of the rabbits was generally more extensive than in 

 the case of the dogs. — {Pfliiger's archiv, xsxi. 215.) 

 W. n. H. [527 



structure of the placenta. — Ercolani has re- 

 newed the advocacy of his views on the mammalian 

 placenta, according to which, after conception, the 

 mucosa of the uterus falls off, and a new cellular de- 

 cidual layer is formed, and after delivery the mucosa 

 is re-formed. ports some new observations, par- 



ticularly on the dormouse and on woman, by which 

 he endeavors to strengthen his position. He writes 

 in the form of letters addressed to Prof. Kolliker at 

 Wiirzburg. Dr. H. O. Marcy, in the New York medi- 

 cal journal {J a\j 28 -Aug. 4), gives an account of 

 these letters, but adds nothing original. The diffi- 

 culty as to Ercolani's views is threefold: he leaves 

 in obscurity the exact histolytical and histogenetical 

 changes in, 1°, the assumed shedding of the mucosa; 

 2°, the appearance of the new-formed decidua ; 3°, the 

 regeneration of the mucosa. For the present, Kolli- 

 ker's view, that the maternal decidua is the meta- 

 morphosed mucosa, has at least an equal claim for 

 acceptance with Ercolani's theory. — (Rendic. accad. 

 sc. ist. Bologna, Jan. 28, 1S83.) c. s. M. [528 



Touch-corpuscles arid other nerve-endings in 

 man and apes. — W. -Wolff has investigated the cor- 

 puscles of touch in Cercopithecus, the chimpanzee, 

 and man. The corpuscles are essentially the same in 

 all. They have an oval form, and are distinguished 

 by having the connective-tissue envelope thrown into 

 folds parallel with their long axis, the folds being 

 delicate and close together. The content of the cap- 

 sule is a granular, coherent fluid. According to Wolff, 

 the supposed nerve-filaments seen in gold prepara- 

 tions are really precipitates formed in the folds of the 

 capsule. 



The author questions whether the nerves have any 

 terminations in epithelium. His principal objection 

 is, that, if the cornea of small animals is macerated 

 for several hours in weak gold solutions, the epithe- 

 lium falls off as a distinct membrane. Now, as gold 

 fixes the nerves, if any filaments ran to the membrane, 

 they would hold it down, and the epithelium would 

 not separate. The author confuses fixing the optical 

 form of the nerves and fixing their coherency. There 

 is no reason against, but, on the contrary, many rea- 

 sons for, assuming a maceration of the nerve-filaments 

 in weak solutions of gold. In view of the very nu- 

 merous positive observations of nerve-endings in epi- 

 thelia, Wolff's argumentation is weak, and it appears 

 unnecessary to follow his further deductions; viz., 



that since glands are modified epithelia, and epithclia 

 have no nerve-endings proper, therefore the gland- 

 cells have no nerve-endings. Such attempts to set 

 aside a vast body of evidence on account of a few im- 

 perfect observations ought not to he countenanced. — 

 {Arch. anat. physioL, anat. ablh., 1SS3, 128.) c. s. m. 



[529 

 The action of digltaline on the heart and 

 blood-vessels. — The authors of this paper, Donald- 

 son and Stevens, have made a careful and thorough 

 study of the action of digitaline on the heart and 

 blood-vessels, and have arrived at results differing 

 from those usually accepted. The evidence obtained 

 by previous investigators is summarized by them as 

 follows: "Investigations on the frog's lieart show 

 an increase of work; investigations on the arterioles 

 have led to contradictory results, with the weight of 

 evidence in favor of a constriction." In their own 

 work they made use of frogs and terrapins. The heart 

 was completely isolated from the rest of the body, 

 and kept alive by defibrinated blood supplied to it 

 from the venous side; while the outflow of blood from 

 the ventricles, in the method used, could easily be 

 determined at any time, and the relative amount of 

 work done by the heart, when pure blood or blood 

 containing digitaline was fed to it, estimated. The 

 conditions under which the heart worked were made, 

 as far as possible, the same as those existing during 

 life. The result of these experiments was that digi- 

 taline causes a decrease in the work done by the heart. 

 On the other hand, digitaline injected into the living 

 animal in moderate doses increases the blood-press- 

 ure. This increase of blood-pressure cannot be caused 

 by the heart: it must result, therefore, from a'con- 

 striction of the arterioles. Experiments were made 

 in which the arterial system was supplied with normal 

 salt solution at a constant pressure, and the outflow 

 collected from the large veins emptying into the 

 heart. The heart was thus excluded from the prob- 

 lem. It was then found, that, when digitaline was 

 added to the circulating liquid, there was a diminution 

 in the outflow from the veins; and this diminution 

 could only be caused by a constriction of the arterioles. 

 The result of their work, then, is that digitaline causes 

 a decrease in the work done by the heart, but increases 

 mean blood-pressure by constricting the arterioles. — 

 {Journ. ofphysiol., iv. 165.) w. H. H. [530 



(J/,m.) 

 Cilia in the human kidney. — That a large por- 

 tion of the renal tubules in cold-blooded vertebrates 

 is ciliated has been known for some time. It has also 

 been known, from the observations of Bowman and 

 others, that the neck of the Malpighian capsule in 

 mammals is ciliated. A. H. Tuttle found, from the 

 examination of a large number of sections of human 

 kidneys, that the convoluted tubule is very exten- 

 sively, if not generally, ciliated. Where the flat lining- 

 cells of the capsule approach the neck, they become 

 cuboidal and ciliated also. The cilia in the kidney 

 are from 3.5 to 5 // long, very fine, numerous, and 

 closely set. Confirmatory observations were made on 

 the kidney of a kitten. The cilia are probably pres- 



