OF THE ANTENN/E OF INSECTS. 885 



the occasion of reading my former paper, were those by E. F. Erichson, published at Berlin 

 in 1847, and contained in his ' Dissertatio de fabricil et usu antcnnarum in Insectis,' in 

 which he states that he has arrived at the following laws : — 



" 1. Antennarum tcstam in insectis nequaquam solidam, sed numerosis poris perfora- 

 tam esse. 



" 2. Poros hosce ab interiore parte membrana tenui clauses esse. 



"3. Poros in variorum insectorum antennis variis modis dispositos esse." 



He then proceeds to show the position of these closed pores in the various forms of 

 antennae, and that they are never foimd on the basal joints. He describes the dilated third 

 joint in Musca as alone possessing these pores, and considers the seta to be the true con- 

 tinuation of the antenna, which view had already been promulgated by Mr. Curtis. He 

 also notices the numerous hairs on the antenna, between the pores, which he considers 

 to form a protection to them from extraneous bodies. Kow these pores he regards as 

 organs of smell ; because, he remarks, the oKactory organs of the higher animals arc moist 

 membranes in order that the odorous particles may be dissolved by the humotir secreted, 

 therefore he doubts not that these membranes perform the same office, protected by the 

 downy hairs, and retained moist by them. Another reason for which he considers them 

 organs of smell, is that they are more numerous in those tribes whose scent is acute. 



Of tliis work I was not aware at the time of reading my former paper, it being very 

 scarce. The plates accompanying it simply show holes or pores, closed in by a delicate 

 membrane. 



Vogt (Zoologische Briefe, vol. i. p. 516-17, Frankfurt a. M., 1851) says, " If these uniform 

 feelers are examined with a sufficiently high magnifying power, the outer sui'face of all 

 the divisions, except the articulating joint, is found to be covered with minute pimctiu-es, 

 which are closed in at the bottom by a thin membrane that appears to be clothed with 

 numerous hairs. In the antennae that are not of a uniform shape throughout, there is a 

 shaft or style, and these pores or indentations are then found only upon the toothed 

 processes, branches, and feathers of the feelers, whilst the iategument of the shaft is con- 

 stituted Kke that of the remaining portions of the body. The peculiar structure of the 

 antennae is, no doubt, closely connected with their functions ; but it would be going far to 

 say, with some recent observers, that it affords imdeniable proofs of the correctness of the 

 oft-contested theory that they are organs of smeU only." He then says, "We are of opinion 

 that these minute pores, filled with fbie hairs, perform a function combining those of smell 

 and touch ; for it is an undoulited fact that many insects, such as Ants, Crickets, and 

 others, constantly employ their antenna? to touch and recognize objects, and that nocturnal 

 creatui-es of this class, especially, possess a remarkably acute sense of touch in the organs ; 

 whilst others, again, as the Longicornia, in which these organs are considerably developed 

 in size and form, make no such use of their feelers. On the other hand, we know of no 

 other organs of smell in insects ; and all attempts to find the seat of this sense have been 

 hitherto ineffectual." 



Thus we see how many diflferent opinions have been entertained regarding the functions 

 of the antennae. Sulzer, Scarpa, Schneider, Bockhausen, Eeaumur, BonsdorfF, Carus, 

 Straus-Durckheim, Oken, Burmeister, Kii-by and Spence, and Newport are all in favour 



VOL. XXII. 3 E 



