THE MAGGOT OF THE BLOW-FLY. 33 



The specimen is thus safely mounted and entirely free from 

 air-bubbles and dirt. In this way, I have made hundreds of 

 transparent sections of Traps, Basalts, Porphyrites, Pitchstones, 

 Obsidians, Granites, Limestones, Flints, Agates, Jaspers, Fossil 

 wood, Teeth, Corals, etc. This process is also suitable for making 

 transparent sections of Bone, Ivory, etc., and is much superior to 

 the old method of rubbing down a specimen fixed with balsam to 

 a glass slip. I have tried both methods. You may now enjoy 

 the fruit of your labours, by examining the finished section under 

 the microscope. 



Many rock-sections show very fine natural colours, but the 

 polariscope works wonders in giving splendid shades of colour and 

 defining the crystalline structure of the Igneous rocks ; whilst on the 

 other hand, many Limestones, Black-Band Ironstones, etc., are 

 seen to be made up of myriads of minute fossil organic structures, 

 closely compacted together in a " paste " of granular matter. 



In selecting specimens of Traps, Limestones, etc., for section- 

 ising, too much care cannot be used in taking notes of the position, 

 formation, and locaHty from which each specimen is procured. 

 When a specimen loses its " pedigree/' it at the same time loses 

 the greater part of its scientific interest and value. 



. ^be fIDagoot of tbe Blow^lfli?* 



By a. Hammond, F.L.S. 



Plate 20. 



THE Anatomy of the Blow-Fly, has, as perhaps most of our 

 members are aware, formed the subject of an exhaustive 

 memoir by Mr. Lowne, in which, however, with the exception 

 of certain details of development, little comparatively is said about 

 the larva or maggot. I propose giving a few notes of my own 

 observations on this subject, for the use of our members. I think 

 it will scarcely need an apology for its introduction to a Micros- 

 copical Society, as every detail must needs be worked out by the 

 aid of that instrument. 



D 



