-860 : The American Naturalist. [April, 
MICROSCOPY." 
Orienting Small Objects for Sectioning, and “ Fixing” 
them, when Mounted in Cells. 
I. In one of the recent “ Contributions from the Zoological Laboratory 
of the Museum of Comp. Zoology,” Vol. XXV, No.3, Dr. W. McM. 
Woodworth describes a method of orienting small objects for the 
microtome. His method was developed, he states, from one first used 
by myself. To avoid any misunderstanding, I will say that in answer 
to a letter from my friend Dr. Woodworth, asking permission to use 
or describe my method, I replied that he was at liberty to make what 
use of it he saw fit, or words to that effect. I refer to the subject here, 
partly because Dr. Woodworth does not state what the original 
method was, or how he has modified or added to it, but mainly because 
I believe the original method is much simpler and better adapted 
to the purpose than his. 
My method, which is especially useful when one desires to orient 
accurately large numbers of small and similar objects, is as follows: 
Small strips of glazed writing paper marked with.two sets of raised 
parallel lines running at right angles to each other are cut, and at uitable | 
intervals a very small drop of thick collodion and clove oil, about the - 
consistency of thick honey, is added. The drops are arranged close 
together along one of the ribs that run lengthwise of the paper. The 
object to be imbedded is cleared in clove oil, or oil of bergamot—not 
turpentine. The latter dries too quickly, so that air bubbles are likely 
to form in the object ; and besides it does not mix readily, as it should, 
‘with the thick collodion. It is then raised on the point of a knife, and 
after the excess of oil is drawn off, transferred to a drop of the thick 
collodion. It may then be adjusted at leisure under the compound 
or the dissecting microscope, and will stay in any desired position. 
When half a dozen or more objects are oriented in reference to the 
cross lines (which are to be parallel to the section planes) the whole 
thing is placed in turpentine. This washes out the clove oil and fixes 
the objects very firmly to the paper. When submerged in turpentine, 
if desirable, the relation of each object to the orienting lines ean be 
redetermined under the compound microscope with greater preci’ 
than before. If any one of them has been inaccurately placed, 1t ie 
still be moved to some extent, but it is better to note the fact, an 
‘Edited by C. O. Whitman, Chicago University. 
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