1894.] Embryology. 529 
For examination in toto, 24 hours in this stain, and then washing with 
distilled water and pure alcohol gave good results. 
Section staining on slide was also found desirable and Safranin was 
the stain used—2} hours, followed by acidulated (3 % Hel) alcohol of 
90 % grade for 7-10 minutes. 
The Schällibaum should be new, the sections carefully applied to a 
well smeared slide, and kept at 60° C. for exactly 15 minutes. 
If Mayer’s albumen fixative is used, only warm, and as soon as par- 
affine is melted remove slide from heat. 
A number of sections of the hermaphrodite duct (h. d. Fig. 1) were 
made. One egg was found, in this duct, near the hermaphrodite 
gland, containing two polar corpuscles, each surrounded with a faintly 
stained Hof, and each showing striae radiating from corpuscle through 
Hof. About 8 chromosomes were observed irregularly grouped in the 
well-defined archoplasm of Boveri.’ 
From these sections it appears that the centres of attraction which 
Garnault® says do not exist in the ovarian egg of Arion and Helix, and 
which were not seen in the hermaphrodite gland of L. maximus, do 
exist in the duct very near the gland. They evidently appear imme- 
diately after the egg has left the ovary. This duct was lined, for the 
most part, with ciliated epithelium, and contained much mucus. 
Fig. 2 illustrates an optical 
section of egg No. 1 from gland- 
ular part of the oviduct (see Fig. 
v o 
. . = oO Ox 
1) viewed obliquely to the long POSE 822 Ow 
axis of the spindl d showi GIS a na 9S 
axis of the spindle, and showing ARSA] Jo 
the two polar corpuscles and 3 Do 4 
chromosomes, there being about 
twenty of the latter lying in an 
irregular cluster in the clear 
space between the corpuscles: 
This egg was stained in picrocar- 
minate of lithium for 30 hours. 
In its examination a Zeiss Oc 2 
and Obj. E were used. A broken 
membrane, “ membrane rougée,” was seen with apparently chromatic 
thickenings in it. Observations on this egg coincide closely with those 
of Garnault on Arion and Heliz, and, in a measure, with those of 
Vejdovsky on Rhynchelmis.® 
1 & Zellen-Studen” von Dr. Theodor Boveri, Jena, 1887. 
5 “Sur les phénoménes de la fécundation chez P Helix aspersa et P Arion em- 
piricorum.”—Zodl. Anzeiger Nos. 297 and 298, Dec., 88 and Jan., ’89. 
ê Die Entwecklungsgeschicete der Oligochaeten (Rhynchelmis) , 1888. 
Fic. 2. 
35 
