56 
Psyche 
[June 
Our studies indicate that while the function attributed 
to the proventriculus by Emery and others is correct, the 
accepted explanation of its mechanics as given above is 
basically erroneous. The reason for this lies in several 
fundamental misconceptions established by Emery in his 
1888 paper and maintained in the literature ever since. 
First, Emery believed that the filter hairs of the euform- 
icine sepal canals actually seal off the canals from the 
calyx cavity : “Die Rinne wird gegen das Lumen des Kelches 
durch das Ineinandergreifen der die Fliigel besetzenden 
Hi'trchen verschlossen”. Because of this he was inclined 
to treat the canals as relatively unimportant structures. 
Subsequent workers, including Forbes, have observed that 
the canals really open into the lumen, but none have con- 
sidered the obvious possibility that they might serve to 
conduct liquid past the occlusory tract. That this conduc- 
tion may occur has been ascertained by our observations 
on the proventriculi of Camponotus fed with stained honey. 
Following spontaneous contractions of the calyx and ejec- 
tion of the contents into the crop, the canals could often 
be seen to remain full of the honey, usually back to the 
level of the occlusory tract, but in one instance through 
most of the length of the bulb as well. In these cases there 
were no evidences of the honey in the bulb cavity itself. 
A second misconception which Emery established is that 
the occlusory tract acts as a valve. Actually, even if the 
occlusory tract could be closed entirely, which is possible, 
the presence of strongly reinforced canals passing through 
the tract prevents it from stopping flow altogether. At the 
same time, the cruciform slit cannot be opened to an extent 
much greater than that shown in plate 6. In all, the entire 
structure of the tract appears to be too rigid to be able 
to exert much control over the rate of flow by the action 
of its intrinsic muscles. 
A third misconception is that the canals of the bulb are 
collapsed as the transverse muscles contract. We have al- 
ready seen that these canals are sealed off in the anterior 
portion of the bulb even when the muscles are relaxed. It 
is probable that they become sealed off but not collapsed 
in the posterior portion as contraction is initiated. Why 
this happens can be seen in an examination of the cross 
