226 CONTRIBUTIONS TO MARINE BIONOMICS. 
Zoology, I., p. 158), but he did not apparently publish his observations 
in full until 1865. 
In the meantime Mr. David Robertson communicated to the Philo- 
sophical Society of Glasgow, on March 13th, 1861, an interesting note 
on the function of these antenne. He described the burrowing habits 
of the crab, and shewed that, under these circumstances, the antennal 
tube preserved “a free passage for the purpose of enabling the animal 
to carry on the process of its aqueous respiration.” Mr. Robertson 
believed, with Gosse, that the current through the tube was exhalent in 
character. In another paper he stated that “he had seen the ova cast 
up through the opening [of the antennal tube]—the inference being 
that the animal had placed it by means of its claws within the influence 
of the current.” (Proc. Nat. Hist. Soc., Glasgow, vol. i. p. 1.) 
Gosse (1865) similarly observed that each antenna, from the form and 
arrangement of its bristles, constituted a “semi-tube, so that when 
the pair was brought face to face the tube was complete.” He also 
carefully watched a living specimen, as it was sitting upright on the top 
of the sand, close to the side of a glass aquarium, and observed that 
the antennal tube formed a channel for a definite current of water. To 
quote his own words: “I immediately saw that a strong current of 
water was continuously pouring up from the points of the approximated 
antenne. ‘Tracing this to its origin, it became evident that it was pro- 
duced by the rapid vibration of the foot-jaws, drawing in the surrounding 
water, and pouring it off upwards between the united antenne, as 
through a long tube. . . .” “I think, then, that we may, with an 
approach to certainty, conclude that the long antennz are intended 
to keep a passage open through the sand, from the bottom of the burrow 
to the superincumbent water, rendered effete by having bathed the gills ; 
and it is one of those exquisite contrivances and appropriations of 
structure to habit which are so constantly exciting our admiration . . . 
[and] are ever rewarding the research of the patient observer.” 
We shall see below that while Gosse’s conduit-theory of the function 
of the antennz is perfectly correct, his inferences as to the function of 
the antennal conduit are true only to a limited extent. Gosse assumed 
that the habits of the crab when beneath the sand were similar to its 
habits when above the sand, and confined his observations to the crab 
in the latter condition. Experiment shews, however, that there may be 
a marked difference in the working of certain organs under the different 
conditions. 
A third theory as to the function of the antenne in Corystes 
cassivelaunus is due to Mr. A. R. Hunt (1885). He says, “I incline to 
think that the function of the antenne is to maintain a communication 
between the buried crab and the water above, as without some such con- 
