1902] MICROSCOPICAL JOURNAL. 131 
a 
again when we view apy objects. I wish it would be 
tried. Remember the contrivance is easy to make, and 
is extremely cheap. 
Notes on the Method of Feeding of Phyllopods and 
| Cladocera. 
MARCUS HARTOG, M. A., D. Sc. 
In the course of some hatching experiments with Apus 
and Branchipus [ incidentally noticed that they fed ly- 
ing on their backs, the swing of the appendages produc- 
ing a backward current of the water down either side, 
while the inmost lobes (“gnathobasites” of Lankester) 
sent an upstream along the median line to the mouth, 
The food consisted of the floating materials in the water, 
and was swallowed by the combined movements of the 
mandibles and the peristaltic action of the gullet. The 
two mandibles work so that the one has greater play 
than the other, carrying the suspended matters past it 
right into the gullet. , : 
It is interesting to compare this with the more com- 
plex arrangements of Cladocera. To study these in 
‘Daphnia, etc., we require a good magnification by alow- 
angle lens, such as the B (4 in.) and C(4 in.) of Zeiss; 
and the animal must lie in a cell, preferably uucovered, 
deep enough to allow it free play. Here the thorasic 
appendages cause a flow of water into the shell through 
the angles on either side between the valves and the 
beaked head, and immediately past the anterior antennae, 
which are thus in the very best position, as sense organs, 
_ for perceiving any change in the properties of the in- 
draught. The stream flows backwards between the 
valves in the space traversed by the limbs proper and 
their pectinate plates. Into the gill-cavities, between the 
valves and the outer side of the limbs, no formed particles 
can be seen to pass, as the pectinate plates on the limbs, 
which make them so efficient in producing the current, are 
