82 The Neuroglia of the Spinal Cord of the Elephant 
Several of the methods devised for the staining of neuroglia allow 
the use of formalin-preserved tissue and the two methods by which the 
best general results are to be obtained (those of Weigert* and Benda ‘*) 
require fixation in formalin. Thus the elephant material on hand, 
having been fixed in formalin, was suited to the purpose. 
I have found paraffin sections much better for the study of neuroglia 
than celloidin sections. The celloidin itself will at best hold a certain 
amount of the stain and thus, under transmitted hght, give a murky 
property to the section detrimental to the sharpness of both image and 
contrast. The Weigert method, as originally given, is a celloidin 
-method. Also it is more applicable to human tissue, having been espe- 
cially devised for such. For purposes of comparison the material here 
in hand was prepared by each of two methods, both of which give fairly 
good results with animal as well as human tissue. These two methods 
are, first, a modification of the Weigert procedure as given by Aguerre * 
and, second, the method of Benda as adapted and employed by Huber 
in his comparative “Studies on the Neuroglia.”* Of the two methods 
the latter gave the better results, both with the elephant tissue and 
with that of the other animals to be mentioned. Though the modifica- 
tion of Weigert’s method of staining neuroglia gave preparations in 
which could be observed all to be noted in sections stained by the latter 
method, yet for sharpness of outline and distinctness of differentiation, 
the procedure given by Huber resulted in a decided excellence. Also, 
with it thinner sections are possible than with the Weigert method. 
Very thin sections, however, are not always necessary nor even best. 
To get an idea of the complexity of the networks of neuroglia fibers, 
the shape of the cells, and the extent of single neuroglia fibers, fairly 
thick sections are desirable. Paraffin sections of 5 w and 8 yw in thick- 
ness proved efficient for the study. Both transverse and longitudinal 
sections were made, and mounted and stained on the same slide. Cer- 
tain of the sections were made from small pieces from a known locality 
of the spinal cord, others from large pieces involving one-half of its 
lateral diameter. All pieces were taken from within the cervical en- 
largement. 
2 Weigert, C. Beitrige zur Kenntniss der normalen menschlichen Neuroglia. 
Festschrift, Frankfurt a. M., 1895. 
3 Benda, C. Erfahrungen tiber Neurogliafarbungen und eine neue Farbungs- 
methode. Neurologisches Centralblatt. Vol. XIX, 1900. 
4Acuerre, J. A. Archiy fiir Mikros. Anat. und Entwicklungsgesch. Vol. LVI, 
1900. Also Neurological Technique (Hardesty) Method XIV, The University of 
Chicago Press, 1902. 
5 Huber, G. Carl. The Am. Jour. of Anat., Vol. I, No. 1, 1901. 
