242 Transactions of the 



II. — The Suctorial Organs of the Bhw-jly. 



By John Anthony, M.D., F.R.M.S. 



{Read before the Royal Microscopical Society, May 6, 1874.) 



Plate LXIV. (Lower portion). 



In bringing 'before the Society the results of careful investigations 

 into the more minute structure of the suctorial organs of Musca 

 carnaria, I have nothing that I am aware of in antagonism with the 

 excellent and conscientious descriptions of the parts of the insect by 

 Mr. Lowne and Mr. Suffolk ; I have rather striven through nume- 

 rous dissections, and the use of the best modern optical appUances, 

 to carry our knowledge a step or two in advance with respect to 

 the mechanism of one of the most curious structures in the insect 

 world. 



The "tongue of the fly" has always been one of the most 

 popular of microscopic objects, and the professional preparer of the 

 well-known shdes has taxed all his ingenuity to squeeze the bulbous 

 fleshy mass of the tongue quite flat, in order to get all detail into 

 the same focal plane. Worse than that, by the use of Canada 

 balsam as a medium in which to mount the parts, there has been an 

 obscuration or obliteration of the major part of the delicate detail 

 which it will be my business to describe ; and I cannot begin my 

 business better than by warning anyone who wishes for the real 

 structure of the " fly's tongue," that one of the commercial shdes 

 bearing that label is about one of the most unhkely places to find 

 it. My examinations of the suctorial organs of the fly were carried 

 on for many months — in fact while flesh-flies were " in season," and 

 I dissected a very large number ere I could satisfy myself that the 

 views I was gradually led to adopt with respect to the mechanism 

 of the tubes were not fanciful. For the dissections I employed the 

 special " Dissecting Microscope" of Smith and Beck — a modificar- 

 tion of that of Oberhauser, afi'ording, like it, a varying amplification 

 from two diameters to about 120, but having the advantage of a 

 special correction in its frds objective for equalizing the definition 

 through this large range of powers. Long practice on minute 

 objects enabled me easily, by aid of a couple of needles, with a suit- 

 able power of this instrument, to take the fleshy lobes of the fly's 

 tongue, to separate the component parts, and to arrange them lor 

 careful examination in the usual compound microscope kept always 

 ready in position, armed with the most modern objectives, and care- 

 fully corrected in every way for errors arising from refraction or 

 faulty illumination. The objective I principally depended upon was 

 a fine |^th of Messrs. Powell and Lealand, and this of course used 

 for transmitted light ; but I took care at the same time, so far as I 

 was able, to view the same structure by reflected light — with of 



