September 15, 1916] 



SCIENCE 



389 



hoi, in a 33'/3 per cent, solution of acetic acid 

 and in a 20 per cent, sulphuric acid solution. 



Concerning Professor Barker's suggestion in 

 regard to the uncertainty as to the previous 

 natural infection of the rabbit used, it should 

 be noted that in the article in the Journal of 

 Parasitology I stated that it could not be 

 positively demonstrated that the rabbit was un- 

 infested at the time it was fed. Attention, 

 however, was called to the fact that spontane- 

 ous infestation among rabbits from the same 

 source was unknown, and it was considered 

 that this was very strong evidence for assum- 

 ing that the cysticerci found in the rabbit re- 

 sulted from the feeding experiment. How 

 strong this presumptive evidence was will be 

 seen from the following : 



The records of the Bureau of Animal Indus- 

 try Experiment station at Bethesda, Md., show 

 that about 5,000 rabbits have been reared and 

 used for laboratory purposes. By inquiry 

 among the members of the bureau laboratories 

 • where these rabbits have been used, it was 

 learned that cysticerci have never been ob- 

 served in any case except as the result of ex- 

 periments in which tapeworm eggs were fed to 

 the animals. As all these rabbits are reared 

 under practically identical conditions and the 

 greater number of them during and subsequent 

 to the experiments in which they are used, are 

 kept until death under essentially the same 

 conditions as my experiment rabbit, it would 

 seem that the feeding experiment with pro- 

 glottids of a triradiate T. pisiformis was very 

 well safeguarded by checks, and that the results 

 though (as was noted) not conclusive, justified 

 the statements which I made to the effect that 

 the feeding experiment in question tended to 

 show that normal larvae may result from the 

 eggs of triradiate adults, and on the other 

 hand that it failed to demonstrate the develop- 

 ment of abnormal larvse from polyradiate 

 adults. In other words, recognizing the inade- 

 quacy of a single feeding experiment, I did 

 not draw any definite conclusions from the re- 

 sults. I accepted these results merely as indi- 

 cating certain probabilities and placed them 

 on record so that they would be available for 

 reference to others who might have opportu- 



nity to undertake feeding experiments with the 

 eggs of polyradiate cestodes. 



Winthrop D. Foster 

 Zoological Division, 



Bureau of Animal Industry, 

 U. S. Department op Agriculture 



QUOTATIONS 



SCIENCE AND COMMERCE 



In commenting on the report of the National 

 Physical Laboratory for 1915-16, Nature re- 

 calls the serious anxiety caused to those re- 

 sponsible for the supply of optical munitions 

 by the shortage of suitable glass at the begin- 

 ning of the war, for the industry of optical 

 glass production had tended more and more to 

 become a German monopoly. With the aid of 

 a grant from the Privy Council Committee 

 for Scientific and Industrial Research, a num- 

 ber of inquiries were instituted. So far the 

 main work has been directed to the production 

 of satisfactory pots, since one of the principal 

 difficulties in the manufacture of optical glass 

 lies in the choice of suitable material for the 

 pots in which it is made. Similar work on 

 heat-resisting materials, and generally on the 

 behavior of the rare earths and other sub- 

 stances at high temperatures, is of great im- 

 portance in a large number of industrial proc- 

 esses, but for such work a technological labora- 

 tory on a large scale is needed, and will, it is 

 hoped, be provided. Other research on chem- 

 ical and other glasses has been done during the 

 year by the National Laboratory, as well as by 

 other institutions. The work is of the utmost 

 national and scientific importance, and our 

 scientific contemporary expresses the hope that 

 the committee will spare no effort " to ensure 

 that it is actively continued and extended, and 

 that in the future no risk shall be run of this 

 fundamentally important industry passing into 

 foreign hands." 



The committee is in a good position to 

 achieve the first object, and the acquisition of 

 scientific knowledge and the perfecting of 

 technical methods will make the attainment 

 of the second possible, but it will not do more ; 

 commercial organization is necessary, and also 

 probably state action. As an example of what 



