G erouli). — Caudina. 
lac. oa. 
rripy. 
Fig. 94. 
Fig. 95. 
Fig. 96. 
Fig. 97. 
Fig. 98. 
Fig. 99. 
Fig. 100. 
PLATE 7. 
Abbreviations. 
Lacunar blood vessel of nl. 
ovary. nl. vt. 
Micropyle. z. r. 
Nucleus. 
Yolk nucleus. 
Zona radiata. 
Section of a nearly full-grown ovum. Merkel’s fluid. X 235. 
The same. Fol’s chromic-osmic-acetic mixture. Biondi’s triple stain. 
X 235. 
Zona radiata. Maceration preparation. X 515. 
Section of a well-grown ovum. Perenyi’s fluid. Ehrlich’s liaematoxy- 
lin and eosin. X 235. 
Ovum taken from the ovary March 19, killed with corrosive sublimate 
and stained 20 hours in alcoholic borax-carmine. Examined in 50 
per cent alcohol. Diameter of egg with envelopes 0.4 mm.; exclu¬ 
sive of envelopes 0.26 mm. The micropyles lie in successive hori¬ 
zontal planes in the order a, p, y, 8. 
Optical section of ovum treated with 1 per cent acetic acid and 
mounted in damar. April. Diameter of egg with envelope, 0.24 
mm.; diameter of egg excluding envelope, 0.19 mm.; diameter of 
nucleus, 0.11 mm. X 230. 
Ovarian egg under pressure. November. Optical section showing 
displaced nucleus and micropyle. 
