June 15, 191 1] 



NATURE 



during the experiment are derived. A review of recent 

 work on this difficult subject is appended to this paper. 



(4) The last paper on our list deals with the egg of the 

 mouse. By most observers the egg of this animal has 

 been regarded as an exception to the rule that two polar 

 bodies are formed during maturation. In order to clear 

 up this point and to settle many other doubtful features 

 of this egg, Prof. Mark and Mr. Long have undertaken 

 an elaborate research involving the examination of looo 

 eggs from 147 mice. The methods employed are given 

 in welcome detail, and a special feature of the apparatus 

 was a balance and recording drum so arranged as to 

 indicate automatically the time of parturition. The histo- 

 logical results show that all mouse-eggs form two spindles 

 and a first polar cell, and that all eggs on coming into 

 contact with spermatozoa form a second polar cell. 

 With regard to details, the authors conclude that the 

 number of chromosomes is twenty. The chromosomes of 

 the first spindle are " tetrads," and show indications of 

 both transverse and of longitudinal fission, whilst those of 

 the second spindle are " dyads," and divide longitudinally. 

 The work is most carefully executed, and is fully illus- 

 trated, but the cytoplasmic structures are scarcely visible 

 in the plates. The paper is one of great value to 

 embryologists. 



THE AMERICAN PHILOSOPHICAL SOCIETY. 



T^HE annual general meeting of the American Philo- 

 sophical Society was held at Philadelphia on April 

 20-22, and more than sixty papers on scientific and literary 

 topics were presented. 



It has been the custom for several years to devote one 

 half-day session to a symposium on some special subject 

 in science. This year the afternoon of April 22 was 

 devoted to this feature, the topic being modern views of 

 matter and electricity ; and the following papers were 

 offered : — The fundamental principles, by Prof. D. F. 

 Cbmstock, of Boston ; radio-activity, by Prof. B. B. Bolt- 

 wood, of New Haven ; thermionics, by Prof. O. W. 

 Richardson, of Princeton ; the constitution of the atom, 

 by Prof. H. A. Wilson, of Montreal. The general con- 

 clusion seems to be that the atom of matter, groups of 

 which compose the molecules of different substances, is 

 built up of much smaller parts, called electrons, identical 

 with the smallest unit of negative electricity. It was also 

 explained how it is possible to estimate the actual number 

 of electrons in any particular atom. As the inertia of 

 an electron emitted from an atom of a radio-active sub- 

 stance, such as radium, has been experimentally proved 

 to be a function of its speed, the evidence is strong that 

 all inertia or mass may be electrodynamic in its nature. 



Physiology. 



The secretion of the adrenal glands during emotional 

 excitement, by Prof. W. B. Cannon, Harvard University. 

 The adrenal glands and the sympathetic nervous system 

 are intimately related. The sympathetic system innervates 

 the glands, and the glands in turn secrete a substance that 

 affects bodily structures precisely as the sympathetic 

 system affects them. The sympathetic system is aroused 

 to activity in states of emotional excitement. Examina- 

 tion of the blood of excited animals reveals the presence 

 of adrenal secretion, which was not found in the blood 

 before the excitement. Possibly the adrenal secretion con- 

 tinues the excited state. Possibly also the adrenal secre- 

 tion caused by emotional disturbances has some of the 

 effects produced by injection of the substance, such as 

 glycosuria and atheroma of arteries. Indeed, two of the 

 author's students, Shohl and Wright, have recently shown 

 that glycosuria can be produced in the cat by fright. The 

 suggestion, however, must be put to further experimental 

 test. 



Coagulation of the blood, bv Prof. W. H. Howell, Johns 

 Hopkins University. The theory of the coagulation of 

 blood most commonly accepted at the present time holds 

 that three of the four necessary factors in the process are 

 present in the circulating blood, but that the fourth, which 

 initiates the process in shed blood, is furnished by the 

 tissues outside the blood or by the disintegration of cor- 

 puscular elements in the blood itself. This fourth factor 



NO. 2172, VOL. 86] 



is an organic substance of the nature of a kinase, which, 

 in conjunction with the calcium salts of the blood, serves 

 to activate the prothrombin, also present in the blood, to 

 thrombin. The thrombin then acts upon the fibrinogen 

 and converts it to fibrin, which constitutes the essential 

 phenomenon of clotting. In opposition to this theory, the 

 author gave experimental evidence to show that in normal 

 blood the fluidity is due to the constant presence of an 

 antithrombin, and that in shed blood the tissue elements 

 furnish a substance, thromboplastin, which neutralises the 

 antithrombin, and thus allows clotting to take place. In 

 the vertebrates below the mammals, the thromboplastin is 

 furnished by the cells of the outside tissues, and without 

 their cooperation clotting would not occur. In the 

 mammals, thromboplastin is furnished by elements in the 

 blood itself, the platetets, so that the blood may clot 

 promptly without cooperation on the part of the outside 

 tissues. In human beings, the condition known as hemo- 

 philia, in which there is delayed clotting and danger of 

 fatal haemorrhage, the defect is due, not to a lack of 

 kinase in the tissues as a whole, the view usually taught 

 at present, but to an excess of the antithrombin normally 

 present in tlie blood. 



The cyclic changes in the mammalian ovary, by Leo 

 Loeb, director of the Pathological Department, St. Louis 

 Skin and Cancer Hospital. In the mammalian ovary 

 cyclic changes of a very far-reaching character take place. 

 They concern the follicles, corpora lutea, and ova. There 

 exists in the ovary a mechanism (in the corpus lutcm) 

 regulating those changes ; the corpus lutem prolongs the 

 sexual cycle, not by retarding the maturation of the 

 follicles, but by preventing the rupture of the mature 

 follicles. The author's recent observations make it very 

 probable that a partial parthenogenetic development of 

 some ova accompany those cyclic changes in the follicles 

 in a certain percentage of animals. 



Electrical Engineering. 



The high voltage corona in air, by Prof. J. B. White- 

 head, Johns Hopkins University. The author Described 

 The limitation to the long-distance electrical transmission 

 of power imposed by the insulating properties of the air, 

 and a new method for determining accurately a voltage 

 at which the air in the neighbourhood of electric wires 

 and cables will break down, and also gave the results of 

 a series of experiments on the influence of the size of the 

 wire, the stranding of the wire into a cable, the frequency, 

 the pressure, the temperature, and the moisture content 

 of the air. He also reviewed the bearing of present 

 physical knowledge on the nature of the phenomena which 

 are involved. 



Geology. 



Supposed recent subsidence of the Atlantic coast, by 

 Prof. D. W. Johnson, Harvard University. The author 

 briefly reviewed the evidence in support of the generally 

 accepted theory that the Atlantic coast is subsiding at the 

 rate of from i to 2 feet per century, and showed that the 

 phenomena supposed to indicate subsidence might be pro- 

 duced by fluctuations in the height of ordinary high tides 

 resulting froip changes in the form of the shore-line. A 

 study of the Atlantic shore-line indicates that conditions 

 are there favourable to marked local changes in the 

 height of the tides, independently of any general move- 

 ment of the land. On the other hand, the structure of 

 certain beaches along the coast afford very strong proof 

 that there can have been no long-continued progressive 

 subsidence of the coast within the last few thousand years. 

 The thcorv of fluctuating tidal heights, and the theory of 

 stability of the land mass, were illustrated by selected 

 examples of shore-line phenomena. ... . n f 



Alimentation of existing continental glaciers, by l rot. 

 W H. Hobbs, University of Michigan, Ann Arbor. It 

 was in the Alps of Switzerland that the early studies, and 

 by far the larger number of subsequent investigations, of 

 glaciers have been made. The Swiss type of glacier is 

 one of the most diminutive, but as the theory of former 

 continental glaciation was derived from these studies of 

 puny glaciers, it is not surprising that their attributes wer.- 

 carried over unchanged to the reconstructed extinct type* 

 thousands, and even tens of thousands, of times lar^si . 



