ARUM MACULATUM AND ITS CROSS-FERTILIZATION. 265 
contained two live flies, and eight or ten dead ones lying at the 
bottom covered with pollen. Most Arum flowers kill a few flies, 
and these may of tio be found in them after the rest have 
escaped; but some kill far more than others, and a few we have 
noticed have apparently killed all, as they contained sometimes as 
many as one hundred dead. 
It seems to us rather like a piece of gratuitous kindness on 
the part of the Arum for it to secrete a drop of nectar for the 
flies just before | their departure, ‘‘thus repaying the insects bate 
their captivity,” as Sir John Lubbock says; for the flies 
hardly enter the spathes for the sake of this honey, as it iin 
not exist when they do so. The plant, presumably, catches 
the insects by its odour, and therefore secures all it requires 
its own ends. But if cold weather were to intervene, the secretion 
of the nectar would probably be retarded, and thus some of the 
insects might starve. The fact, however, that most Arums kill 
some flies makes one think that they must have a definite object in 
so doing. We do not wish to state our belief that this object is the 
obtaining of nutriment from the bodies of the dead flies, but an 
observation which Mr. Christy has made formerly led us to believe 
that this might possibly be the object. He has frequently seen 
dead flies stuck to the tips he fter the r d 
escaped, and on several of fe occasions he lainly observed 
that these flies’ bodies ha n b eans or ot 
tip of one of these ovaries, whilst the other wing was drawn into 
the ae of an adjoining one with such force that the right wing had 
been torn from tbe body. This might, however, have been 
nooomiplinli by the swelling and dais growing apart of the 
two ovaries rather than by suction. 
With these facts before us we a ourselves whether it 
could be that Arum was insectivorous, and, if not, on what 
other supposition could we account fii the eee evidence ? 
Being unable to answer these questions, we applied to Mr. A. 
Bennett, ais has taken a very kind interest in our observations. 
His reply was as follows:—‘‘I have examined under the micro- 
scope several of the specimens of Arum you have been kind 
nough to send me, but find no evidence 8 any absorption or 
sti is th 
stigmatic opening, there being no style; this opening is fringed 
with hairs, which are evidently the stigmatic hairs, and have for 
their Seaction the excitement of the emission of the pollen yen 
