RESPIRATORY METABOLISM. 



yeast mixture as used by geneticists and others working with flies 

 i I'earl 3J. The experimental animals were kept in 100 cc. cul- 

 ture bottles in an electric incubator at 25 C. Small square pieces 

 of filter paper were put in the culture bottles so that the larv.i 

 could crawl up on them and pupate. The filter paper with the 

 attached pupa.- were- removed at regular intervals and pupa; of 

 known -hu- obtained. The pupae were carefully removed 



from the filter paper, cleaned and washed, then sterilized in 115 

 per cent, alcohol and again washed. They were then put into 



A B 



different types of - used in CO. ib-ti-rmina- 



roximatcly 250 cc. which can be used either 



ml. ml respiration chai: .me as A. (.' shows attach- 



ment "l" .mima: (e) as well as tr . />, r n charnlxr. 



hooks fur hold. s of 



S3 to allow indicator solution \ run from flask 



tube without coming in contact with supports of 



a ; c. glass animal holder or spoon; d, glass-ground 



:s for animal holder or spoon. Apparatus is made 



i-ntinly of l'yri\ -r Non-sol glass wi'h no rubbi r stoppers or connections. 

 .loi: 11 ground. 



.small >hell vials obtaining small pieco of moistene<l filter paper 

 in prevent drying. The vials were marked, stoppered with a small 

 i "i ton pluu and kept in the incubator at _>5 C. Great care is 

 iiecessary in handling individual pupae because of their small size 

 and the fact that they are easily injured. A very thin metal spat- 



