ARUM MACULATUM AND ITS RELATIONS WITH INSECTS 231 
L. Crown Hills, Evington, c. fr. ; Neg. ce. fr. — H. Schrebert 
Willd. Charnwood Fore st; Swithland Wood, : Nera woods 
near Ashby-de-la-Zouch ; Bardon HL Nailsto: ood. 
Hylocomium splendens 'B.&S. Que uenby ; ; Tilton Hill; Swithland 
Wood ; Bardon Hill, c.fr., Bloram; Lea ton : Thedding worth.— 
H. brevirostre B. & 8. Anstey, J. F. Hollin 
ARUM MACULATUM AND ITS RELATIONS WITH 
INSECTS.* 
By Joun Gerarp, §.J., F.L.S. 
As is well known, drum maculatum is habitually visited by 
dager piserides, » small dipterous insect, of which specimens 
e almost always to be found in the chamber formed by ae ower 
nasiela of the spathe, sometimes in large numbers. The story of 
their Mass poe with the plant has frequently been cetsietnis 
Germany by Hermann Miiller, Knuth, and others; in our own 
country by Lord Avebury, and many popular writers who have told 
e as their own. There are, however, various reasons for 
thinking that the truth of the matter is of a darker and more tragic 
character than we should thus be led to su 
It need hardly be said that the inflorescence of the Arum is 
borne on a cen teal spadix within the chamber, open only at the 
top, lying at the base of the large involucre or spathe, which con- 
tracts just above it, and then expands upwards into the well-known 
hood, open. in front, wherein is displayed the purple knob in which 
the spadix terminates. At the bottom of the spadix are found the 
female flowers arranged in a sa cluster around the central 
column; above them are the male flowers, their anthers almost 
sessile, in in a similar ring. The upper female flowers are usually 
infert tile, “ghd terminate in long filaments. Above the male flowers 
is another ring of filaments, generally regarded as staminodes, or 
abortive stamens, which are situated in or near the narrow throat 
leading into the basal chamber. These filaments are frequently 
described as stiff hairs or bristles, and are said to point downwards, 
so as to permit the ingress of insects, but preclude egress, like the 
spikes of an eel- or lobste r-pot. 
According to Miiller, who tells the story most fully, the Arum 
is incapable of self- fertilization, being proterogynous, so that by ve 
time when the stamens begin to shed their pollen the pistils are 
ieee capable of being a tilizd Wek which it ition. follow t that 
the first drum of the s in any locality must r arren 
The sll howerer, abel aithar by the “ f foul ammoniacal 
sce d by the plant, or by the prospect of shelter or 
th “tthe Arum is wa to produce heat in a sensible degree)— 
anti "the chamber, and, having done so, are compelled to make a 
x Th, Tuiced £ ddr gee oS iecna Society, June 15, 1905. : 
