182 EVENINGS AT THE MICROSCOPE 



it occupies nearly the whole breadth of the organ, and is 

 smaller than at its termination near the mouth, where the 

 concavity or groove does not occupy more than about one- 

 third of the breadth. In some species, the extremity of 

 each maxilla is furnished along its anterior and lateral 

 margin with a great number of minute papillae. These, in 

 Vanessa Atalanta (the Eed Admiral Butterfly), for instance, 

 form little barrel- shaped bodies, furnished at the free end 

 with three or more marginal teeth and a larger pointed body 

 in the centre. There are seventy-four of these in each 

 maxilla, or half the proboscis. Mr. Newport regards them 

 as probably organs of taste. There are also some curious 

 appendages arranged along the inner anterior margin of 

 each maxilla, in the form of minute hooks, which, when 

 the proboscis is extended, serve to unite the two halves 

 together, by the points of the hooks in one half being in- 

 serted into little depressions between the teeth of the op- 

 posite side; sometimes these are furnished with a tooth 

 below their tips. 



With all deference for so respectable an authority, I 

 cannot help seeing that such is not the structure of the 

 antlia before us. It is evident to me that each half tube 

 is composed of a membrane stretched upon stiff horny 

 semi-rings, doubtless composed of chitine, and certainly 

 not muscular. By bringing the outline of the rounded 

 exterior into focus, we see that these rings form sharp 

 ridges; and by tracing them onward to the attenuated ex- 

 tremity of the organ, we see them gradually give way to 

 transverse lines of interrupted ridgy warts upon the out- 

 side of the membrane. The true muscles appear to be in- 

 dicated by those oblique lines and bands that are seen in 

 the interior, beneath the horny rings. 



