Mat 19, 1916] 



SCIENCE 



721 



plex material; and breeding from spores with es- 

 sentially pure lines is especially favorable for 

 securing more definite data in reference to the 

 possibilities of variation and inheritance. 

 The Dynamics of Antagonism: W. J. V. Ostee- 



HOUT. 



If two toxic substances antagonize each other 

 we call this action antagonism. An accurate meas- 

 ure of antagonism is afforded by determining the 

 electrical resistance of living tissues. Toxic sub- 

 stances cause a fall of resistance, but if in a mix- 

 ture of two such substances resistance falls less 

 rapidly, it is evident that this is due to antagon- 

 ism. In the case of the common kelp Laminaria 

 NaCl causes a fall of resistance while CaCl; causes 

 a rise followed by a fall of resistance. In mix- 

 tures of NaOl and CaClo the resistance rises and 

 then falls; by using the right proportions the fall 

 may be made very gradual. We may explain 

 these facts by assuming that the resistance is due 

 to a substance, the production of which is accele- 

 rated by CaCl. while its decomposition is checked 

 by a compound formed by the union of both NaCl 

 and CaCL with a substance in the protoplasm. 

 This throws new light on the manner in which 

 salts act in preserving life. It has been found 

 that the electrical resistance is a very delicate and 

 accurate indicator of the vitality of protoplasm, 

 since any kind of injury is at once indicated by a 

 fall of resistance. This permits us to give a 

 quantitative meaning to such terms as vitality, in- 

 jury, recovery and death. The mechanism by 

 which changes in resistance are produced by salts 

 is therefore of great importance. The facts here 

 presented give us a new insight into this mechan- 

 ism. 



Jointing as a Fundamental Factor in the Degrada- 

 tion of the Lithosphere : Frederick Eheenfeld. 

 (Introduced by Professor Amos P. Brown.) 

 This paper is a study of those physical activi- 

 ties which are always at work to bring the surface 

 of the earth down to a level or nearly flat surface. 

 It includes also some discussion concerning the 

 probable destruction of former great land masses 

 or continents such as those believed by geologists 

 to have existed formerly across the present oceans 

 connecting Europe, Africa and America. In most 

 text-books of the science the question of land sur- 

 face leveling or degradation is considered more 

 from the standpoint of the atmospheric or other 

 surface cause than from the point of the construc- 

 tion of the solid portions of the earth itself. This 

 the author of this paper considers a somewhat mis- 



taken view to take of the case, as the stony mass 

 or portion of the earth has been shown by many 

 geologists to be subject to a constant fracturing 

 or jointing which shows itself in various ways such 

 as influence on river drainage, repeated groups of 

 islands, bays along sea coasts and in certain types 

 of volcanic and earthquake appearances. The 

 paper discussed these and also the subject of ma- 

 rine planation to produce a lowering of the land 

 below sea level. Illustrations of such marine ac- 

 tion were shown from the Maine coast and also 

 from the forms and positions of some of the At- 

 lantic ocean islands. This subject of the action 

 of the sea to produce a general leveling though a 

 much discussed one some decades ago has been neg- 

 lected by many modern students, but is now be- 

 coming prominent under newer ideas of the sci- 

 ence, and this paper is in part a study of jointing 

 in the mass of the lands to assist in such action 

 and hasten continental land leveling and destruc- 

 tion by creating in the rock mass through joints 

 great lines of weakness which under the attack of 

 both the atmosphere and the sea compel the fall- 

 ing apart of the land. The question of former 

 great land masses was discussed, as was also the 

 bearing of these joints in the subject of the for- 

 mation of coral reefs. In conclusion the author 

 proposed a "law of joints" in which the control- 

 ling influence of joint lines was more definitely 

 stated. 



Sinlcing Islands versus a Rising Ocean in the 

 Coral-Seef Problem: William Morris Davis. 

 Since Darwin 's voyage in the Beagle, eighty years 

 ago, nearly all geologists who adopted his theory 

 of coral reef accepted also his postulate that the 

 reef-bearing islands have subsided with the sub- 

 siding ocean bottom. In later years, and largely 

 under the leadership of the Austrian geologist, 

 Suess, and the German geographer, Penck, the pos- 

 sible variation of ocean level around fixed islands 

 has been emphasized. When it is seen that a rise 

 of the ocean surface around still-standing islands 

 would produce all the conditions that arise from 

 Darwin's postulate of subsiding islands in an 

 ocean of constant level, search should be made for 

 some means of evaluating these two alternatives. 

 The result of such a search shows that the theory 

 of a changing ocean involves many extravagant 

 complications which have not been sufiiciently con- 

 sidered by those who accepted it; while the theory 

 of subsiding islands is relatively simple and eco- 

 nomical. Darwin's original theory is to be pre- 

 ferred on those grounds. 



