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186 General Notes. 

mented by an exhaustive analytical comparison of the facts observ- 
ed, with a view to their right classification and interpretation." 

Papers on the topics were to be read by Hon. A. C. Butts and 
Hon. Geo. H. Yeaman, of the New York Bar ; Judge Calvin G. 
Pratt, of Supreme Court, Brooklyn, N. Y. ; Foster L. Backus, 
Esq., of Brooklyn ; Prof. J. J. Reese, of Univei"sity of Pennsyl- 
vania; William J. Mann, Esq.; E. P. Thwing, M.D.; Prof. 
Moritz Benedict, of Vienna, and others. 

The Bar Association of the District of Columbia has proposed 
an international or interstate law congress, to be held in the city 
of Washington, on the 22d of May, 1888, to which shall be invited 
representatives of all other bar associations, judges of courts, pros- 
ecuting officers, and lawyers whose eminence in their profession en- 
title them to that recognition. I do not know whether this will 
result in a permanent organization or not. But if so, I would, sug- 
gest and strongly urge that it should have a section devoted to 
criminal anthropology ; and that anthropologic societies and con- 
gresses should do the same. By this means professional lawyers 
who are amateurs of anthropology, and professional anthropologists 
who may be amateur lawyers, would have opportunities for the 
accomplishment of great good in their respective sciences. 



MICROSCOPY. 



Geblach's Embryoscope. 2 — The embryoscope, devised by Dr. 
Gerlach, supplies a great and long-felt desideratum in experimental 
embryology. It is a mechanism for closing hermetically, a circular 
opening, made with a trepan, in the shell of the hen's egg ; and it 
serves the purpose of a window, through which the living embryo 
may be directly observed, and its development followed from day 
to day. 

The instrument consists of two parts : 1. A mounting-ring 
(Aufsatzring) to be firmly cemented to the egg-shell. 2. A key- 
piece with glass front, which screws into the ring and closes it 
air-tight. 

In the Cut. A represents the embryoscope in perspective, and B, 
in section. The metallic mounting-ring is 1J mm. thick, and has 
a lumen 2 cm. in diameter. The lower edge (Ar) is bevelled and 
saddle-shaped so as to fit the equatorial surface of the egg, while the 
upper edge is flat. From the outer surface of the ring, two 
square-cornered bars (Z) project in opposite directions. On its 
inner surface, a little above the lower edge, is a diaphragm {Md) 

1 Edited by 0. O. Whitman, Milwaukee. 

2 Anatom. Anzeiger, II, Nos. 18 and 19, 1887, p. 583. 



Microscopy. 



187 



with an opening 13 mm. in diameter. Resting upon this diaphragm, 
and corresponding with it in size and shape, is a second diaphragm 
of thin wax-cloth ( Wd), which serves as a packing-washer for the 
key-piece. 

The key-piece of the embryoscope consists of a low, metallic 
cylinder, closed by a disk of glass ((?), which represents the window 
that is to cover the artificial opening in the shell. The upper part 
of the cylinder expands peripherally to form a rim with a milled 
«dge. This rim has two notches opposite each other, into which 
fit the arms of a small wrench, by the aid of which the key-piece 
can be tightly screwed down. There is also a short, narrow, verti- 
cal canal (Vo) or vent, the lower end of which must open in the 
middle of the key-piece ring. 

The accessory apparatus required in the use of the embryoscope 
consists of (1) a trepan, (2) a guide-ring for the same, (3) a metallic 
jork, and (4) the key or wrench before mentioned. 



Vs. < 




The above-named pieces, together with a punch to cut wax-cloth 
diaphragms, and six embryoscopes, may be obtained from Reiniger, 
Gebbert, and Schall, Erlangen, for 36 marks, or from the Educa- 
tional Supply Co., 6 Hamilton Place, Boston. 

The trepan is a thin, metallic cylinder, 2 to 21 cm. long, the lower 
end of which is toothed, while the upper part is fluted and serves 
as the handle. The diameter of the trepan is a trifle smaller than 
that of the opening of the diaphragm. The object of this is to 
leave a very narrow zone of shell, covered with shellac, inside the 
inner edge of the diaphragm. 

The guide-ring for the trepan has the same construction as the 



188 General Notes. 

key-piece, except that it has no glass disk. It serves to steady as 
well as guide the trepan during the process of cutting. 

The fork has two notches at the ends of its prongs, fitted to 
receive the two bars of the mounting-ring. When adjusted to the 
bars, the fork serves as a means of holding the embryoscope 
securely, while screwing or unscrewing the key-piece. 

The wrench, the use of which has already been explained, is similar 
in construction to the wrench used for mathematical instruments. 

The mounting-ring is fastened to the egg by means of a cement 
consisting of two parts of wax and three parts of colophonium. The 
cement is hard and brittle at the ordinary room-temperature, but 
becomes soft and kneadable when held in the hand for a few 
moments. After warming the mounting-ring over a gas or a 
spirit lamp, a roll of the softened cement is pressed into the space 
which must be completely filled between the lower face of the 
diaphragm and the lower edge of the ring. As soon as the ring 
becomes sufficiently cool, it is pressed firmly to the equatorial 
surface of tha egg, and the excess of the still soft cement, which is 
thus forced outward and inward beneath the ring, should be 
removed before it becomes brittle, by the aid of a small, sharp- 
pointed blade. In order to avoid injuring the blastoderm, which 
might occur if the hot ring were fastened to the shell directly over 
it, it is best to fix the ring to the side rather than the top of the egg. 

After the ring has been securely fixed and the superfluous cement 
removed, the exposed edges of the remaining cement, seen beneath 
the lower edge of the ring and the inner edge of the diaphragm, 
must be covered with a coat of an alcoholic solution of yellow 
shellac. This may be applied with a small brush, care being taken 
to cover the cement completely, and as little of the egg-shell as 
possible. 

After the shellac has dried, a process which is completed in 
twelve to fourteen hours in the open air and in six hours in the 
incubator, the shell may be trepanned. 

Antiseptic precautions are required in opening the egg. An 
oblong porcelain trough or glass dish is first filled with a 3% 
solution of carbolic acid, and in this are placed the instru- 
ments to be used in the operation : a glass rod, a medium-sized 
brush, small shears, forceps, the trepan, and the guide-ring. Before 
using, these instruments are dried with carbolized cotton, and after 
using returned to the dish of carbolic acid. 

After washing the hands in dilute sublimate or carbolic acid, a 
perfectly fresh egg is painted with the three per cent, solution of 
carbolic acid, and then dried with carbolized cotton. The small 
end of the egg-shell is then cut out with the shears, and the thick 
white poured with the aid of the glass rod into a clean dish, leaving 
the yolk and the thinner white in the shell. The white is to be 



Microscopy. 189 

used in screwing in the key-piece, and must therefore always be 
prepared beforehand. 

After these preparations, the egg to which the mounting-ring has 
been cemented is disinfected in the manner above described, and 
placed in an egg-carrier with the ring uppermost. The inside of 
the ring is then brushed with carbolic acid, which is shaken out 
after one or two minutes and replaced by a \°f solution 
of common salt, which is also allowed to remain from one to 
two minutes, and then completely removed by means of carbolized 
cotton. The guide-ring is now screwed in, and the egg trepanned 
from the side, in order to avoid injuring the blastoderm. The egg 
is next placed with its opening upward, and the guide-ring removed. 
When the trepan is withdrawn, the excised piece of shell often 
comes with it, and sometimes the underlying shell-membrane. If 
this is not the case, the two pieces must be removed separately by 
the aid of the pincers. Care must, of course, be taken not to 
injure the blastoderm and the zona pellucida. 

The thin white, which was left with the yolk in the shell, is 
allowed to flow over the glass rod upon the exposed blastoderm 
until the ring is filled, care being taken to avoid air bubbles. The 
wax-cloth diaphragm is next taken from the dish of carbolic acid, 
dried in blotting-paper, drawn through the thick white, and inserted 
in the ring in close contact with the metallic diaphragm ; and then 
the key-piece, previously washed with carbolic acid and dried with 
carbolized cotton, is slowly screwed down. The superfluous white 
is thus slowly forced out through the vent ( Vo), until the key-piece 
reaches the diaphragm and closes the vent. Finally, when the 
strength of the hand is no longer sufficient, the egg with its embryo- 
scope is placed in the metallic fork, and the wrench applied until 
with this means it is no longer possible to turn the key-piece 
farther. 

The process of trepanning and inserting the key-piece is some- 
what more complicated in the case of eggs that have already been 
incubated, as the egg and the fluids employed must be kept warm. 
A water-bath is required, consisting of a low tin box, filled with 
water, and provided with covered apartments for the reception of 
the egg, the thin white, the carbolic acid, and the salt solution, 
which are in this way maintained at a proper temperature. In 
other respects, the mode of procedure is exactly the same as given 
above. 

The key-piece may be removed as often as desired, provided the 
above precautions are taken each time in inserting it. If the key- 
piece is unscrewed by means of the fork and wrench, it must, of 
course, be washed in the warm carbolic acid, and the vent cleared 
by the introduction of a wire. 

The egg must be placed in the incubator with the embryoscope 



190 General Notes. 

on one side. If it is placed upward, the respiration of the embryo 
is hindered. The embryoscope can be turned up at any moment, 
and kept upright for five minutes at a time without injury to the 
embryo. 

With a little practice, the whole process of arming an egg with 
the embryoscope may be completed in from six to eight minutes. 

The embryoscope is well adapted for purposes of class-demon- 
stration, for investigating the growth of the various parts of the 
embryo, and the physiological processes during embryonic life, as 
the action of the heart, movements of the body, etc. It is indis- 
pensable to him who would study the effects of external agents 
upon the embryos of warm-blooded animals; and must be of great 
service where it is required to determine the precise stage of devel- 
opment before removing the embryo from the egg. It has been 
found useful in studying the formation of double embryos. Fene- 
strated eggs have been successfully incubated up to the thirteenth 
day, and it is probable that under favorable conditions the embryos 
of such eggs would reach maturity. 

On the fifth day, it is still easy to bring the embryos under the 
window. On the sixth and seventh days, it is more difficult. At 
this period the change in the position of the embryo, which requires 
from five to ten minutes, should take place in the incubator. 

After the eighth day, the embryo cannot be brought under the 
window. If it be necessary to determine whether such an egg or an 
older one still lives, we have only to leave the egg for several hours 
in the incubator with the window directed upwards a little, after 
which, by strong reflected light, one may readily see the blood 
circulating through the channels of the vascular area. 



PROCEEDINGS OF SCIENTIFIC SOCIETIES. 

Academy of Natural Sciences of Philadelphia. — Sept. 
20, 1887. — Mr. G. H. Parker gave an historical sketch of investi- 
gations upon the eyes of arthropods. Grenadier's theory of the 
hypodermal origin of the retina, developed by involution, has been 
borne out by later studies. From a study of the nerve distribu- 
tion, the speaker believed the three-layered eye to be evolved from 
that with one layer. 

Mr. Meehan stated that in Mesembryanthemum and similar 
plants, the glands of which develop in inverse proportion to the 
roots, chemical analysis sometimes determines the presence of more 
nitrogen than can be obtained from the soil. It was suggested that 
the glands absorbed the gas from the atmosphere. 

Mr. H. T. Cresson exhibited specimens of prehistoric implements 
collected from beds surrounding what had probably been pile dwell- 
ings on the mud flats of the Delaware, near Naaman's Creek.