198 
Jan. 31, 1911. The Queensland Naturalist. 
Reprints. P^om H. Tryon, Notes on the Wild Cochineal 
Insect, &c., and Notes on the Protection of Native Birds in 
Queensland. P^rom Royal Australasian Ornithologists’ 
Union, The Emu, December (s])eciai number dealing Avith 
-the Tenth (Brisbane) Session). 
CANNI BALI STIC ROTIFERS. 
In the December number of Knoiiiedge, )\Ir. Charles 
P^. Rousselet, the well-known authority on Rotifers, wiites 
of the cannibalistic tendencies of these microscopic animals. 
The devouring of its own kith and kin is not common 
among the Rotifera, but Ploesorna Imdsoni is not at all 
scrupulous in this respect. ‘‘ Of all the Rotifers this is 
the most vigorous swimmer ; it rushes through the w ater 
at great s])eed, snapping at any other Rotifer that comes 
in its way, carrying it in its mouth and devouring it with- 
out a moment’s pause, it is not at all particular as to 
Avhether its victim is a EynchaMa or its own sister or cousin ” 
Mr. Rousselet witnessed a case where one Rotifer w'as SAval- 
loAved by a second, and the latter was in turn cajitured 
by a third Ploesoma, and he sto])ped the tragedy by killing 
and mounting all the dramatis personae in the midde ot 
the performance. Mr. W. R. C^olledge informs us that 
he has not so far taken Ploesoma hudsoni in the vicinity 
of Brisbane, the only species of that genus obtained by 
him being Ploesoma lenficulare. At one of the meetings 
of the Club last year Mr. Colledge stated that Asflanchjia 
amphora, one of the largest species in Australia, Avas also 
cannibalistic. On lifting one by a pipette from its native 
element he dropped it rather sharply on a microscopic 
slide. The shock it sustained by the process disturbed 
its nervous equilibrium, and it apparently felt sick. So 
it began to relieve itself of the contents of its stomach by 
using its loosely attached incudate jaAvs as forceps. These 
plunged into the interior of its digestive organ, pulled 
out the half-digested form of a Rotifer of its OA\n kind, 
and laid it down on the slide. Another dip into the bag, 
and up came a Brachionus ruhens ; then folloAved three 
Anuraeas, and lastly a Scirfopoda. These Avere all laid 
side by side. Hoav many more Avere contained in its capa- 
cious maw he did not know, for it here succumbed to the 
shock and the subsequent surgical operation, but from 
appearances there must have been at least half a dozen 
left as a testimony of gormandizing propensities. 
