98 
might readily seize upon such a type among birds, as an 
example of a missing link restored; but he would be misled 
by an aspect without a reality. In like manner, Prof. Owen’s 
claim of “the transitional character which it manifests to 
the Pterosaurian order,” rests upon a foundation, striking 
indeed to our minds, but hardly sustained by a close study 
of homologies. A genetic connection between the life 
of successive ages, must have been influenced by other 
laws than those of gradual modification alone; and evolu- 
tion is a process far more elaborate and far less understood 
than pure Darwinism would allow. 
Mr. WituiAM Fake made the following communication : 
Experiments with Poisons on Limulus. 
During a sojourn in Connecticut last summer, I caught a 
number of horse-shoe crabs, (Limulus polyphemus). 
Being struck with the idea of trying the effect of poisons on 
them, I procured a hypodermic syringe, and injected two 
grains of morphia sulphate, about half an inch below the 
cephalic shield, on the under side, into the soft parts. About 
fifteen minutes after the injection, the crab showed slight 
signs of being under the hypnotic influence of opium, but 
only fora short time. After this, five grains were injected, 
and with more effect, as the crab ceased crawling about, and 
rested on the floor of the laboratory. On turning him on his 
back, he appeared quite in a state of unconsciousness, in- 
terrupted only at long intervals by a slow aud peculiar con- 
traction and expansion of the chele, 
When struck with a stick, the crab became conscious again 
for a few seconds, trying to turn over and regain his normal 
position; but he was unable to do so, and would soon fall 
back into his narcotic slumber. I left him over-night in a 
corner of the laboratory, but by morning, he had, to my great 
surprise, turned over and crawled to the other side of the 
room, being again quite active. 
I then injected one drachm of hydrocyanic acid, (2 per ct.,) 
which only acted as a powerful sedative, the crab being un- 
willing to move about. Another drachm was introduced, but 
this time into the soft parts where the telson is articulated to 
