200 THE AMEBIC AN MONTHLY [November, 



Fifth Row. — In the fifth row are i6 scales from the wings of Lepidoptera 

 (butterfly). These are the darker elongated objects, three-toothed on the 

 outer margin. Alternating with them ai*e i6 longer objects resembling in 

 outline double-convex lenses. These are diatoms of the genus Surirella. 



Sixth Roxv. — The i6 diatoms in this row, called Actinocyclus., are like 

 those in the third row, and are each placed at the crenate ends of the butterfly 

 scales of row number five. 



Seventh Row. — Here 48 more wheels of Chirodota are arranged in triplets 

 outside the Actinocyclus of row number six. 



Eighth Row. — The 16 oval-shaped objects in this row are spines or scales 

 of Synapta. This genus belongs to the Echinoderniata., order Holothuria 

 and abounds in the Adriatic sea. These plates, as they are called, project 

 from the surface of the skin and serve somewhat the same purpose as the 

 wheel-like plates on Chii-odota^ an allied genus to Synapta. Each of these 

 calcareous plates carries seven oval disks of considerable size and as many 

 more minute ones at the outer end. Alternating with these plates are trip- 

 lets (48 in all) oi Actinocyclus^ like those in other rows. 



Ninth Row. — The ninth or outer row is made up of 16 anchors of Sy?iapta, 

 and 48 diatoms, Surirella. The latter are like those in the fifth row. The 

 anchors are from the same genus as the scales in row number eight. These 

 anchor-like spines grow attached to the acute ends of the plates described above. 



The whole constitutes a remarkable illustration of recent art, not only in 

 microscopy but in photography and engraving. 



Washington, D. C, October 20, 1888. 



Notices of Microscopical Methods.* 



By Dr. M. NIKIFOROW, 



MOSCOW. 



I. A carmine for nuclear staining. — In spite of the immense number of 

 stains at present in vogue, carmine, at first discovered by chance, remains in 

 many respects the best. A modification of carmine staining, valuable either 

 for isolated nuclear staining or for difllise staining, either of the section or of 

 the piece in toto., is as follows : — 



First. Boil in a porcelain dish 3 parts of carmine, 5 parts of borax, and 100 

 parts of water. 



Second. To this mixture, which will not dissolve the carmine thoroughly, 

 add ammonium hydrate until the carmine dissolves. The color of the solu- 

 tion will now be cherry-red. 



Third. Carefullv neutralize the solution with acetic acid and the color will 

 change to a beautiful rose tint. 



The section may now be stained in the neutral carmine, if nuclear staining 

 alone is desired, or it may be stained in carmine with an excess of acetic acid 

 if diffuse stain is wished. For sections, 15 minutes will be enough in the 

 stain, but the section may remain 24 hours without injury, and for pieces 24 

 hours will be required. After staining, the excess of staining fluid is to be 

 washed out by immersion m distilled water until the water ceases to be tinted 

 by the piece. The color works best in alcohol-preserved material, but can 

 also be used with chromic acid specimens if they have not lain in chromic 

 acid two weeks or over. By adding a very minute quantity of carbolic acid 

 to the ammonium-borax-carmine solution the growth in it of moulds will be 

 prevented. 



II. Safranin for staining central nervous tissue. — Prof. Adamkiewicz 

 first called to attention that safranin would give with nerve tissues hardened 



* Condensed and paraphrased from the original article in Zeits. f. Wiss. iVIikros., Sept., 1888, p. 337. 



