PROCEEDINGS OF SOCIETIES. 279 



at the top and bottom, you got something like what Dr. Anthony 

 figured, but inside instead of outside. Dr. Anthony says he had used 

 polarized light. He (Mr. Slack) had tried polarized light, placing 

 the polarizer imder a j\ condenser, and fixed the analyzer just over 

 one of Powell and Lealand's immersion iths. With that he got abun- 

 dance of light. When the prisms were so arranged as to give a 

 perfectly luminous field, the tojis of the sujiposed pillai'S j^ermitted 

 the light to pass freely, and they looked white, with a little shading 

 off at the edges. By turning the prisms so as to get a perfectly dark 

 field, all the thick parts of the scale became brilliantly luminous. 

 The margins or rims of the supposed columns were quite bright, and 

 the centres dark. Hollow pillars covered with thin membranes might 

 produce these effects. Among some peculiarities he had noticed in 

 the most perfect scales series of ridges or ribs. One of the scales 

 viewed as an uncovered object suggested the idea that the true form 

 of the markings might be that the columnar pillar referred to was 

 formed by bifurcations of the ribs, the ribs opening and the two halves 

 uniting again so as to make hollow columns, 



Mr. Hogg, referring to Mr. Wenham's remarks, said he tliought 

 Dr. Anthony looked upon these peculiar battledore scales as some- 

 what allied to glandular structures in animals. This species of 

 butterfly was mostly found " on the banks where the wild thyme 

 grows," and it was quite probable that they sucked the essential oil 

 from the flowers of the plant, and stored it up in these scales, which 

 occupied an intermediate position beneath the more brilliantly- 

 coloured scales, and the membraneous structure of the wing. It 

 was somewhat remarkable that these scales were only found on the 

 wings of males. This would seem to favour the notion that the oily 

 fluid stored up in them might in some way contribute to the greater 

 brilliancy of the plumage of the males and cause them to be more 

 attractive to their female companions. Mr. Hogg took exception 

 to some of the terms employed by the various speakers, as those of 

 " tubules," and " tuberoular elevations," which did not convey the 

 same meaning, although drawn exactly alike. Mr. Slack, he th(jught, 

 was right in his representation of the structure in question, and in 

 speaking of it as " a tuberculatcd membrane," that is, a raised j)art of 

 the membraneous portion of the scale. Whereas, if Dr. Anthony's 

 representations were correct, the structure consisted of a stalk or 

 pedicle, terminated by a nodulated extremity projected out from the 

 surfiice of the membrane. In such a case it could not be called (uhtr- 

 cula'ed in the sense in which the term was usually employed. 



Mr Stewart said he had lately examined some dry specimens of 

 the battledore scales of Pohjommatus Alexis and of other Lycfenida3. 

 He quite agreed with Mr. Anthony as regarded the shape of the stud- 

 like bodies, but thought they were situated between and not outside 

 the membranes of the scale. 



The battledore scales of P. Alexis were sj^oon-shaped, having the 

 hollow of the bowl directed towards the membrane of the wing ; they 

 were inserted into the wing at an angle of 4.5°, close to the point of 

 attachment, and underneath the larger .scales. 



