iS94. 
371 
of the animal j^i'ojecting through the carapace where the valves 
diverge. 
The tail shows five abdominal segments besides the triple caudal 
spine at its extremity. The first segment is i inch long ; 
second and third are each f inch ; fourth is f inch ; and fifth 
is 1^ inches. The tail diminishes from 1;^ inches to J inch at 
the base of the telson. The first three segments are marked by 
fine lines parallel with the articulating joints, and turning 
abruptly backward near the margin. The spines are long, gently 
tapering, and sharp. The central one is largest, 2i inches long, 
and is articulated with the fifth segment. The two smaller 
spines seem to articulate with the central one near its base. 
THEORIES OF EVOLUTION 
15 Y EDWARD 15. POULTOX. 
In dealing with theories of evolution, I think that we sliall all 
be agreed that we may leave out of consideration the question of 
the origin of life, and deal only with what has happened to life 
after its appearance, however that may have taken place. On 
this subject we shall probaldy most of us still agree with the 
opinion of Darwin'^, that we are not in a position to even speculate 
or think upon that question. — tliat any speculation about it 
is almost a waste of time. And this, I think, remains true in 
spite of the magnificent results of t!ie organic chemists in produ- 
cing chemical bodies by synthesis, which before had been regarded 
1 Read February 7, 1894. 
2 111 Life aud letters. 
