274 



SCIENCE 



[N. S. Vol. LII. No. 1342 



Journal has been replaced by a single issue 

 covering the whole meeting. Clearly it will 

 be a strenuous time. To-day eleven of the 

 twelve sectional presidents deliver their ad- 

 dresses, on subjects ranging from the consti- 

 tution of the stars to the intensive cultiva- 

 tion of gooseberry bushes. The detailed pro- 

 ceedings of the sections in the morning and 

 the afternoon should be full of interest. An 

 announcement is to be made as to the third 

 of the three practical tests proposed by Ein- 

 stein for his new theory of relativity, two 

 having been already successfully passed. The 

 chemists are to consider the production of 

 alcohol for industrial purposes. The geology 

 of the district and the possible effect of the 

 narrow valleys in provoking feelings of im- 

 prisonment and isolation on their thronged 

 population are to engage the attention of the 

 geologists and geographers — imfortunately, in 

 two separate sections. The economists are to 

 discuss decimal coinage, the Danish credit 

 system, and the business side of agriculture, 

 while the agriculturists are busy over the 

 growing of potatoes. The importance of psy- 

 chology, the mental effects of alcohol, and 

 training in citizenship are all on the day's 

 program. In the evening. Professor Herd- 

 man, president-elect, will be inducted into the 

 chair, and will discourse on Oceanography 

 and Fisheries. The following days, if not 

 quite so arduous, are at least to be well filled. 

 Since the Association held its first meeting, 

 at York in 18.31, there has been a great ad- 

 vance in science, and an increasing specializa- 

 tion of its branches. At first there were only 

 six sections, and the next year, at the Oxford 

 meeting, these were reduced to four, dealing 

 respectively with mathematics and physics, 

 chemistry, mineralogy and electricity, geology 

 and geography, biology. By 1855 they had 

 grown to seven; they are now twelve, and a 

 proposal for still further sub-division is to be 

 discussed. We wonder if it is all gain. The 

 reverse tendency is also at work, and several 

 sections are to combine for occasional joint 

 discussions. There is much to be said in 

 favor of a concentration at the annual meet- 

 ings on subjects whose problems concern many 



different branches of science and require il- 

 lumination from many points of view. — The 

 London Times. 



SPECIAL ARTICLES 



EXPERIMENTS IN THE TRANSPLANTATION OF 



THE HYPOPHYSIS OF ADULT RANA 



PIPIENS TO TADPOLES 



The writer has for some time past been 

 engaged in experiments upon the extirpation 

 of the hypophysis and the thyroid glands of 

 tadpoles. These experiments have yielded in- 

 teresting results. Absence of the thyroid gland 

 wholly prevents metamorphosis while the re- 

 moval of the pars buccalis of the hypophysis, 

 i. e., all but the posterior lobe brings about 

 the following results: 



1. Failure to metamorphose. 



2. Retardation of growth in size. 



3. A striking change in color from black 

 to a silver white. 



4. Lowered resistance to unfavorable con- 

 ditions. 



Experiments in transplanting of the hypo- 

 physis were undertaken by the writer two 

 years ago, but failed because of faulty tech- 

 nique, and were for the time being abandoned 

 owing to press of other work. This year the 

 experiments were carried through with sur- 

 prisingly little diiEculty and have given such 

 striking results that it seems well worth while 

 to offer a brief and necessarily rather super- 

 ficial account of them at this time. These 

 experiments are based on 384 operations upon 

 tadpoles. 



It is well known that the hypophysis is 

 composed of fom* elements : the anterior lobe, 

 intermediate lobe, pars tuberalis, and posterior 

 lobe. All but the last named come from the 

 same embryonic anlage — the portion that has 

 been removed in the extirpation experiments 

 mentioned. For the sake of brevity we shall 

 speak of these as " pituitaryless " tadpoles. 

 For the present work three out of the four 

 lobes — all except the pars tuberalis — ^were em- 

 ployed. In each case a fair amount of care 

 is exercised to prevent infection but these 

 precautions are in no case perfect. Greatest 

 reliance is placed upon the remarkable resist- 



