245 



Reproductive organs of female Cepheus} ■*, . D -vr; cuap i 

 tegeocranus ... ... ... ) 



Daphnia Schocfferi ... ... ... Mr. T. S. Morten. 



Bloom of Masdervallia sp. ... ... Mr. F. A. Parsons. 



Melicertatyro... ... ... ... Mr. C. Le Pelley. 



Trans, sec. leaf and stem of Halcea ... Mr. J. W. Reed. 



Long. sec. stem, petiole and bud of ditto ... ,, 



Trans, sec. Leaf of Indiarubber plant ... Mr. W. D. Smith. 



Diatoms, Campylodiscvs horologium ... Mr. G. Sturt. 



Attendance — Members, 55 ; Visitors, 8. 



March 9th, 1883. — Conversational Meeting. 



The fourth of the series of demonstrations was given by Mr. E. T. Newton, 

 F.G.S., on " Some Methods of Preparing Parts of Insects for Microscopical 

 Examination." 



Mr. Newton observed, in his opening remarks, that as these demonstrations 

 were chiefly intended for the benefit of young workers in microscopy, it 

 was not intended to bring forward new methods so much as to show by 

 actual manipulation how certain pieces of microscopic work were done, Mr. 

 Groves having in a previous demonstration fully described the methods of 

 hardening, staining, section-cutting, and mounting. 



Mr. Newton then proceeded to show how he had been in the habit of pre- 

 paring a series of sections of an object, and for this purpose the head of a 

 cockroach {Blatta orientalis) was taken. The head, which had previously 

 been hardened in spirits of wine, was imbedded in wax, and a series of 

 slices cut with a razor in a microtome. These sections were placed upon a 

 series of numbered glass slips, and the staining, cleaning, and clarifying 

 done without removing the sections from these slips, on which, after treat- 

 ment with turpentine to remove the wax, they were mounted in Canada 

 balsam. 



Another series of sections were then prepared from the head of a Blatta, 

 which had been stained entire, and after soaking in absolute alcohol, and 

 then in essential oil, had been put in warm wax. When cut, these sections 

 only required to be treated with turpentine, and then mounted in Canada 

 balsam. 



Mr. Newton next exhibited the model of a Blatta' s brain, which bad been 

 shown and described to the Club in January, 1879 (see " Quekett Journal," 

 Vol. v., p. 150), and explained how, by means of a series of sections, this 

 model had been prepared. 



The following objects were then exhibited in illustration of the demon- 

 stration : — 



Head of Blatta stained carmine, brain in situ. 



Head of Blatta stained aniline black, brain, &c, in situ. 



Head of Wasp stained carmine, brain in situ. 



Head of Grasshopper stained carmine, showing optic ganglia. 



Journ. Q. M. C, Series II., No. 5. t 



