December 12, 1919] 



SCIENCE 



543 



year, to experiment with other animal mem- 

 branes. As a result I found that the metliod 

 outlined below proved uniformly satisfactory. 



The skin of a freshly killed or of a pre- 

 served frog was cut at the junction of leg and 

 trunk. This cut, entirely encircling the leg, 

 permitted the skin of the leg to be peeled off 

 precisely as a glove is removed from the hand. 

 At the knee joint it was necessary to proceed 

 carefully to avoid tearing the skin. Having 

 pulled the skin off as far as the foot, the bones 

 and sinews were cut. The result was a leg- 

 shaped sac, open at the top, containing the 

 bones of the foot at its lower end, and entirely 

 free from perforations. The sac was pulled 

 over the end of a glass tube about twelve 

 inches long, and securely fastened by several 

 turns of strong thread. A strong solution of 

 dextrose was poured into the open end of the 

 tube, and the tube shaken until the liquid 

 passed, drop by drop, down into the sac. This 

 process was continued until the liquid stood 

 about an inch high in the tube. The ap- 

 paratus was supported in such a way that the 

 sac of skin was completely immersed in a 

 tumbler of water. The level of the liquid was 

 recorded by putting a small label on the tube, 

 and the apparatus was ready for demon- 

 stration. 



The apparatus and procedure described above 

 have the following advantages over any other 

 method that I have seen : 



1. Simplicity. — Parts are to be found in any 

 biological laboratory. Entire apparatus can 

 be set up in fifteen minutes. 



2. Reliability. — It is a very simple matter 

 to secure a water-tight junction of the sac 

 and tube by taking several turns of thread 

 and tying the sac tightly to the tube. 



3. Rapidity of Action. — Since there is a 

 large surface exposed to osmotic action, the 

 rise of the liquid in the tube is rapid. It is 

 not uncommon to note a rise of one centi- 

 meter in twenty minutes. This is a valuable 

 point, for it makes possible the recording of 

 data and results in the same laboratory period. 

 A narrow label may be fastened to the tube 

 to mark the level of the liquid at the begin- 

 ning of the hour. The data are given the 



pupil, a sketch of the apparatus is made, and 

 by that time the liquid has risen enough to 

 make possible the recording of the new level 

 and the drawing of conclusions. After the 

 contents of the tumbler have been tested with 

 Fehling's solution, pure water may be substi- 

 tuted, and the experiment repeated. 



Elbert C. Cole 

 HAETroED Public High School, 

 Hartford, Conn. 



why not government-maintained 

 fellowships? 



In recent number of Science,^ Mr. E. W. 

 Nelson has called attention to the many op- 

 portunities that exist in Washington for re- 

 search in connection with the various govern- 

 ment bureaus. To the end that these oppor- 

 tunities may be more widely appreciated he 

 suggests a closer cooperation between the uni- 

 versities and these bureaus and he suggests 

 that universities might find it possible to 

 maintain fellowships which would permit 

 their holders to work at Washington. 



That such opportunities exist is undeniable 

 and there are doubtless a very large number 

 of workers who would be extremely glad to 

 take advantage of them, but that any uni- 

 versity will be able to establish even a single 

 fellowship of this type is almost too much to 

 hope for. The number of fellowships of even 

 the ordinary character is still far too few. 

 However, there is another angle from which 

 the matter may be approached. 



Why should not the federal government 

 itself maintain a group of such fellowships? 

 The presence in Washington of the Congres- 

 sional Library, the ISTational Museum and the 

 various government bureaus has at times been 

 used as an argument in favor of the establish- 

 ment there of a National University. Whether 

 such a university should be established is per- 

 haps debatable and whether if it were estab- 

 lished it could effectively utilize these special 

 opportunities is more so. In fact it probably 

 could not. But in the absence of such an 

 institution, or perhaps even in addition to it, 



1 Nelson, E. W., ' ' Cooperation between Zoolog- 

 ical Laboratories and the Government Bureaus," 

 Science, XLIX., 409, 1919. 



