THE OVARIAN EGG. 295 
intellectual conception which spans the whole 
series of geological ages, and is perfectly consist- 
ent in all its parts. In this sense the present 
will indeed explain the past, and the young 
naturalist is happy who enters upon his life of 
investigation now, when the problems that were 
dark to all his predecessors have received new 
light from the sciences of Paleontology and 
Embryology. 
