1884] Microscopy and Histology. 447 
ious method of constructing models of objects from serial sec- 
tions, By the aid of the camera the outlines of the sections are 
transferred to wax plates, which are then cut out so as to corre- 
spond in outlines as well as dimensions to the sections equally 
magnified in all three directions. With plates thus prepared, it 
is only necessary to put them together in the proper order to 
in a complete model. The method is simple and extremely 
useful, especially in investigating objects with complex internal 
cavities, 
Born has made use of the method in studying different parts 
of the vertebrate head; Swirski, in elucidating the development 
of the shoulder-girdle of the pike ; Stohr, in tracing the develop- 
ment of the skull of amphibia and teleostei; and Uskow, in 
studying the development of the body cavity, the diaphragm, etc. 
An illustratian of the method.—Born makes use of three rect- 
angular tin boxes of equal size, each measuring 270""%230"™ 
X2%™™". Sections should be made about 3™™ thick (never thin- 
ner than j™"). If we desire to construct a model of an object 
from serial sections 4™™ thick, which shall be magnified 60 
diameters, then the wax plates must be made 6o times as thick as 
sections, 2.2., 2™ thick. 
The surface of a plate that could be made in a box of the 
above named dimensions, contains 62,1000™™; and the volume 
f such a plate 2™™ thick would therefore be 124.2°™. The 
Specific 
pT as 5 MEET eg a ena ~ 
ONT 
Fo gravity of common raw beeswax amounts to 
d r> it requires only to be melted and a little turpentine 
o 
ag tin box is first filled 144° deep with boiling water, 
and eg the melted wax poured upon the water. If the water 
€ wax are quite hot, the wax will generally spread evenly 
ofa e; if gaps remain, they can be filled out by the 
has sti E tide drawn over the wax. As soon as the plate 
the walls i and while it is still soft, it is well to cut it free from 
box mi; ha the tin box, as further cooling of the water and the 
Lae Ganse it to split. By the time the water becomes tepid, 
can be removed from the water to some flat support, an 
completely stiffened. Half a hundred plates may thus be 
The Coia course of a few hours. : 
i of the section are transferred to the plate in the 
