290 Proceedings Columbia Biochemical Association [Jan. 



doubtful whether these bodies play an important röle in the absorp- 

 tion of the tail of the tadpole. 



With reg-ard to the basophiles and eosinophiles, it will be seen 

 that they occur in smaller numbers in individuals undergoing meta- 

 morphosis than in young tadpoles and, so far as the basophiles are 

 concerned, they are fewer in number in larvse than in adults. The 

 reverse is the case with the eosinophiles, being found in small num- 

 bers in the adult. The small mononuclear leucocytes occur in 

 smaller numbers in the "absorbing" animals than in either of the 

 other types. They are regarded by the investigators mentioned 

 above as the young, indifferent, forms of the several types of 

 leucocytes and probably, also, of the erythrocytes, but since they 

 occur in larger numbers in the blood of the adult, this view is not 

 borne out by the results of the present investigation. 



It may be concluded, then, from this set of data, that leucocytes 

 do not play an important role in protein and other transfer in the 

 involuting tadpole tail nor do they initiate the process. 



51. Laboratory hints. Max Morse. {Boardman Labora^ 

 tories, Trinity College, Hartford, Conn.) 



An ULTRA-FILTER. Colloids may be filtered to advantage by 

 coating the surface of an alundum filter-disc, placed in a Buchner 

 funnel, with a thin collodion Solution and applying the funnel to a 

 pump, or the house vacuum. The first drainage through the filter 

 will be coarse, the finer suspensions Alling up the interstices of the 

 filter disc; afterwards, fine particles filter. 



A CONVENIENT HOT-WATER BOTTLE HOLDER. Sclcct 3. FloreUCC 



flask with a neck whose sides are as nearly parallel as possible for a 

 distance and wrap half a yard of quarter-inch twine around the neck, 

 spirally ; then wrap electrician's tape or surgeon's tape around the 

 whole, again spirally, thus keeping the twine from unwinding. The 

 heat does not soften the rubber of the tape sufficiently to cause it to 

 leave the twine. If in place of the twine, small round leather belt- 

 ing be used, the apparatus is perfectly satisfactory for all time. 

 The belting may be obtained in any sewing-machine shop or in a 

 belting supply house at small cost. 



52. The diffUsion of iodo-eosin from ether through rubber 

 into ether. Jacob Rosenbloom. (Laboratory of Biological 



