OBITUARY. 
27 
now shows the contrary to be the case, and that one plant may 
nourish many distinct forms of Puccinia, and that one Puccinia may 
be found on very diiferent plants. He also shows that the grouping 
of the spots formed by the fructification of these fungi depends more 
upon the plant that nourishes it than upon the fungus, and that these 
characters cannot be regarded as specific. 
On the Bed-bug and its Allies. By Professor Leidy. — In the 
western part of our country, observed Professor Leidy, I frequently 
heard that bed-bugs were to be found at any time beneath the bark of 
the cottonwood and the pine. In these positions I never found one, 
nor have I ever found the insect except in the too-familiar proximity 
of man. Recently, when in the west, while watching some cliff 
swallows passing in and out of their retort-shaped nests, built under 
the eaves of a house, I was told that these nests swarmed with bed- 
bugs, and that usually people would not allow the birds to build in 
such places, because they introduced bed-bugs into the houses. 
Having collected a number of the bugs, as well as others from the 
interior of the house, specimens of both of which are submitted for 
examination by members, I found that while the latter are true bed- 
bugs, Cimex lectularius, the former are of a different species, the Cimex 
hirundinis. 
The bugs infesting the bat and pigeon have likewise been recog- 
nized as a peculiar species, with the name of G. pipistrelli and G. 
columharius. Professor Leidy further noticed that the habit of the 
G. hirundinis was similar to that of G. lectularius in the circumstance 
that the bugs during the daytime would secrete themselves in 
crevices of the boards away from the nests. After sunset he had 
observed the bugs leave their hiding-places, and make their way to 
the nests. From these observations it would appear as if the peculiar 
bugs of the animals mentioned did not reciprocally infest their hosts.* 
OBITUARY. 
We very much regret that we are unable to give any adequate 
biographical notice of our late friend, Dr. Lawson. We have done 
our best to procure some details of his life previous to his residence 
in London, but have not yet received the promised assistance of our 
friends in Birmingham, where he was Professor of Physiology at 
Queen’s College. 
On coming up to London he was first lecturer on Histology at 
St. Mary’s Medical School, and afterwards lecturer on Physiology 
and the paid physician. At that time he did some good original 
work in the anatomy of snails, and denied the existence of an ovo- 
testis. He also, before Gunther, proved that whitebait are young 
herrings. He also wrote a paper on the lungs, heart, and blood-cor- 
puscles of the slug, and others on the anatomy and physiology of 
gasteropods. 
‘Proc, Nat. Sci.,’ I’hiladelpfiia. 
