April 8, 1904.] 



SCIENCE. 



587 



of Tischeria malifoUella were illustrated by 

 photographs and photomicrographs. 



F. S. Shiver, 

 Secretary. 

 Clemson College, S. C, 

 March, 1904. 



THE ACADEMY OP SCIENCE OF ST. LOUIS. 



The academy held a regular meeting on 

 March 7, Mr. Edwin Harrison presiding. 



Dr. C. A. Snodgrass, city bacteriologist 

 and pathologist, read a paper on the subject 

 ■* Bacteria and Their Work,' illustrated with 

 drawings and cultures. He gave a clear 

 conception of the place occupied by the bac- 

 teria in the living world, and the important 

 work they were doing. He emphasized the 

 fact that bacteria must not be confounded 

 with disease. The following were some of 

 the topics discussed: The distribution of bac- 

 teria on the globe; nitrogen fixation; changes 

 in bacterial flora in milk supplies ; the bacteria 

 of the Illinois, Missouri and Mississippi 

 Eivers; symbiosis; immunity; biological fac- 

 tors that affect bacteria; the relation of hu- 

 man and bovine tuberculosis, and various 

 methods by which infection occurs. 



THE ELISHA MITCHELL SCIENTIFIC SOCIETY OF 

 THE UNIVERSITY OF NORTH CAROLINA. 



The 153d meeting was held in the Physics 

 Lecture Room, Tuesday evening, March 8. 

 The following papers were presented : 



Professor A. S. Wheeler: ' Meroerization.' 



Professor I. H. Manning : ' The Work of the 

 Digestive Glands.' 



Professor Charles Baskerville : ' Kunzite, 

 the New Gem; Its Unique Properties' (with 

 demonstrations ) ,' 



A. S. Wheeler, 

 Becording Secretary. 



DISCUSSION AND CORRESPONDENCE. 



dr. castle AND THE DZIERZON THEORY. 



In a recent number of Science (March 4, 

 1904), Dr. W. E. Castle offers some criticism 

 of my paper entitled ' The Origin of Eemale 

 and Worker Ants from the Eggs of Partheno- 

 genetic Workers,' published in the same jour- 

 nal December 25, 1903. My paper was writ- 



ten for the purpose of calling attention to 

 certain observations which go to show that 

 worker ants can produce worker offspring, 

 probably from unfertilized eggs. I indicated 

 the possible bearings of such observations on 

 current theories of sex, instinct and natural 

 selection. Incidentally, I protested against 

 the wording of the Dzierzon theory in such 

 terms as to preclude further investigation of 

 certain phenomena covered by it, against a 

 premature extension of the theory to groups 

 of social insects less perfectly known than 

 the bees, and against its use in bolstering up 

 other hypotheses. 



Castle pleads guilty to having used terms 

 like ' invariably ' in formulating the Dzierzon 

 theory, but tries to evade the point by remark- 

 ing that ' it scarcely requires explicit state- 

 ment here that all conclusions of inductive 

 science must be so qualified,' that is, by using 

 such expressions as ' so far as observed ' in- 

 stead of ' invariably,' ' always,' etc. It is 

 difficult to see what Castle gains by this state- 

 ment unless he wishes to imply that all the 

 conclusions of inductive science are on the 

 same dead level of probability — Dzierzon's 

 theory, the circulation of the blood, the etiol- 

 ogy of cancer, the rotation of the earth and 

 what not. 



After virtually admitting that I was justi- 

 fied in objecting to his formulation of the 

 Dzierzon theory. Castle feels called upon to 

 present the arguments in favor of that theory, 

 all of which are well known to every tyro 

 in zoology. , The remarks prefacing Castle's 

 disquisition show that he regards the Dzierzon 

 theory as sufficiently and satisfactorily estab- 

 lished, and any expression of doubt concerning 

 some of its implications as certainly useless 

 and possibly heretical or even malicious. He 

 desires to ' join issue ' with me ' sharply.' Al- 

 though I am by no means opposed to the Dzier- 

 zon theory, I accept the challenge, both be- 

 cause I do not wish to disappoint Castle and 

 because his presentation of my views amounts 

 almost to misrepresentation. 



Since its promulgation more than half a 

 century ago, there has never been a time when 

 the Dzierzon theory lacked opponents, both 

 among the bee-keepers and among zoologists 



