162 SUMMARY OF CURRENT RESEARCHES RELATING TO 



WiNKEL, 11.— Apparat zum Markiren mikroskopischer Objecttheile. (Apparatus for 

 luarkine: parts of microscopic objects.) 



Title only of German Patent, Kl. 42, No. 4365. 



Wood, E. W., Jun. — A simple Polariscope. 



[Black glass substituted for the mirror for the polarizer. Eighteen circular cover- 

 glisscs for the analyser.1 



The Microscope, VI. (1886) pp. 268-9 (1 fig.). 



Zeiss's (C.) Ten Thousandth Microscope, 



[He " recently placed in a box with his own hands the ten thousandth Microscope 

 he has made.''] 



The Microscope, VI. (1886) p. 284. 



/3. Collecting', Mounting and Examining Objects, &c.* 

 (2) {h) Preparing' Special Objects. 

 Preparing Eyes of Mammals.t — The eyes of certain mammals used by 

 i)r. A, Dostoiewsky were hardened in Midler's fluid for periods varying 

 from a few days to several moutLs. Many of the eyes had previously 

 been placed for 24-48 hours in a 2 or 3 per cent, chromic acid solution. 

 For cutting, the anterior half of the eye was imbedded in celloidin used in 

 three different strengths (thin, medium, and thick). In each of these 

 solutions the preparation was left for at least 24 hours. It M'as after- 

 wards immersed in a mixture of 2 parts of ordinary spirit and 1 part of 

 water. The direction of the sections was meridional, transverse, and 

 tangential. For staining, Bohmer's hsematoxylin and eosin were exclu- 

 sively used. The logwood solution was several months old, and very 

 weak. This device prevented the celloidin from becoming stained. 



Preparing Eyes of Birds.| — Dr. W. B. Canfield, in his researches on 

 the accommodation apparatus of the bird's eye, employed Semper and 

 Fredericq's method for dry preparation, and also the celloidin process. 

 The eyes were fixed in Miillor's fluid, and then hardened in spirit. For 

 decalcification, saturated solution of picric and chromic acid, and nitric 

 acid 2 per cent, were used. The eyes were then imbedded in celloidin by 

 Czermak's method, and the sections, stained with heematoxylin and eosin, 

 were mounted in balsam. 



Prepariog MoUuscan and Arthropod Eyes.§ — In elucidating the 

 structure of molluscan and arthropod eyes, Mr. W. Patten notes the satis- 

 factory results obtained by the following methods : — When sections were 

 not resorted to, the tissues were hardened a very little and then macerated. 

 The use of chromic acid had to be varied in strength and temperature, &c., 

 for different regions ; it was found especially useful to shift in half an hour 

 from a one-tenth per cent, to a one-twentieth, in 24 hours back again to 

 one-tenth, in 24 hours to a one-fifth, where it was kept for 48-60 hours. 

 The cornea was best treated with picro-chromic, the lens with picro- 

 sulphuric, the layer of nerve-fibres below the septum with one-fifth per cent, 

 chromic acid for 24 hours, the retinophoraB with chromic, the rods and 

 retinidia with one-fifth per cent, chromic at 50^ C. for half an hour. The 

 best preparations, with all the parts in the most natural position, were 



* Tliis subdivision contains (1) Collecting Objects ; (2) Preparing, (a) in general, 

 (b) special objects; (3) Processes prior to making sections; (4) Cutting, including 

 Imbedding and Microtomes; (5) Staining and Injecting; (6) Mounting, including slides, 

 cells, preservative fluids, &c. ; (7) Examining objects, including Testing; (8) Mis- 

 cellaneous mutti-rs ; ('.)) Bibliography. 



t Arch. f. Mikr. Aiiat., xxviii. (1886) pp. 91-121 (2 pis.). 



X Ibid., pp. 121-70 (3 pis.). § MT. Zool. Stat. Neapel, vi. (1886) pp. 733-8. 



I 



