■IM) 



Naturalist. 



[April. 



somewhat larger j)in. As i:i-t as the pins carrying the objects are 



inserted the cork is replaced in the tube, which is filled 



with alcohol. A half dozen fish or amphibian ova may $9* 



be oriented on the same cork. If desirable to draw the 



objects in situ a piece of lead may be pinned to the cork 



and the whole immersed in a small beaker of alcohol. || I j 



The corks carrying the oriented objects are transferred ||| J 



successively to tubes containing the different solutions. [J J 



When ready for final imbedding a piece of porous paper jfjr- J 



is wrapped about the tubes and cork and pinned. The 



cork is now removed, allowing the imbedding solution 



to fill the paper tube thus formed. A lead is fastened 



to the cork and the whole placed in chloroform until |fjl 



hardened, after which the paper is cut from the mass 



and the pins drawn through the cork, when it is ready t °" \ 



for sectioning. This method offers many advantages in ^- -^ 



that several objects may be cut at the same time, FlG-II . 

 drawings may be made after orientation, the ob- 

 jects are transferred from one solution to another more rapidly, etc. 

 In cutting, care should betaken that the knife is placed as obliquely 

 as possible and kept constantly wet with 70% alcohol. For this pur- 

 pose an ordinary pipette pr6vided with a large rubber bulb is used. 

 As fast as cut the sections are drawn back on the blade of the knife, 

 by means of a needle, and arranged in a single row until the blade is 

 filled. To remove them a heavy paper spatula is placed directly upon 

 the section to which it adheres and may be drawn off the edge of the 

 knife and transferred to the slide. By slight pressure together with a 

 rolling movement the section is left in the desired position. Sufficient 

 alcohol is kept on the slide to prevent drying but not enough to allow 

 the sections to float. When the requisite number have been arranged 

 they are covered with a strip of toilet paper which is held on the slide 

 by winding it with fine thread. The sections being thus firmly held 

 in position may be stained, etc. They should not be placed in absolute 

 alcohol but cleared from 95% in a mixture of equal parts of bergamot 

 oil, cedar oil and carbolic acid. When cleared the excess of fluid is 

 removed by a piece of blotting paper ; with gentle pressure sections 

 which are by chance loose are firmly fixed in position, the thread is 

 now cut, the strip of paper rolled back, balsam and cover applied. 



If the object can be stained in toto, which is often the case, much 

 time may be saved by the following method : The stained object is 

 imbedded in the usual manner, but after hardening in chloroform, and 



