342 The Microscope. 



through which the whole series can plainly be seen, must be care- 

 fully removed, leaving the sections on the object-glass. If any sec- 

 tions should remain on the paper, the latter, after the sections in 

 question have been moistened with oil, is replaced in its former 

 position on the object-glass, pressed a little, and then removed, or if 

 the sections are quite dry they may be taken with pincers and trans- 

 ferred to the object-glass. 



As soon as all the sections are in order on the object-glass, the 

 smooth surface of the blotting-paper is laid on it and stroked lightly 

 several times with the finger to remove all the superfluous oil. 



The Canada balsam and cover-glass may now be added without 

 danger of displacing the sections. Entire removal of the oil insures 

 the preservation of the most fugitive colors. The sections should 

 not be placed near the edge of the cover-glass, as every discoloration 

 begins at the edge. 



In the foregoing manner, over 100 sections were placed in a 

 complete series under one cover-glass, in as short a time as by the 

 paraffin methed. 



As celloidin, like paraffin, does not readily penetrate chitinous 

 envelopes, cuticula and cocoons, care should be taken : — 



1. To use at first very thin solutions, which should be grad- 

 ually brought to the concentration which the imbedding mass is to 

 have. 



2. To imbed twice, the first time merely to cut the object in 

 pieces, or open a cocoon, or cut, etc., with the microtome. 



ABSTRACTS. 



The Vinegar Eel. — The mature female is about one-tenth of 

 an inch in length, the mature male one-fifteenth, but both sexes 

 vary in size. The body is long and filiform, of nearly uniform 

 thickness, tapers gently toward the head, but less gradually toward 

 the tail, which ends in a long, fine spine. (Fig. 1). The females 

 are viviparous, and the young may be seen in a mature female 

 inside the body. The two sexes are much alike in external appear- 

 ance, the only difference being that the tail of the male has three 



