624 REPORT OF COMMISSIONER OF FISH AND FISHERIES. [18] 



often happens when an inchuling mass is employed from wliicli the sec- 

 tions must l)e freed before mounting." 



Bindei-s method of maluu/ permanent glycerine mountings. — Mr. Jacob 

 Binder, of Phihi(lelphia,(;ommends the following sim})le method of mount- 

 ing objects in glycerine, which may be found useful in conjunction with 

 the preceding method of treating the eggs of salmonoids proposed by 

 Henneguy, though it hardly seems probable that as good results can 

 be got by the collodion method of embedding, which is recommended, as 

 by some others. 



Mr. Binder finds Bell's cement the best, and with it he draws a ring 

 "with a pencil upon the slide, which he allows to dry for twenty -four 

 hours. Then another coat of the cement is applied on the top of the 

 first ring with the aid of a turn-table. The mounting is then made with 

 glycerine; the superfluous mounting material which is forced out from 

 under the cover may then be washed off by holding the slide under a 

 water-tap. The slide is then allowed to dry when the mouutiug is fin- 

 ished by the addition of another ring of Bell's cement around the edge 

 of the cover, when the preparation is finished. 



Mar¥s methods of treating the eggs of Limax. — For hardening the ova 

 and fixing the nuclear structures this investigator used a 1 per cent, so- 

 lution of osmic acid, the eggs being subsequently stained in Beale's 

 carmine. He also used 1 to 2 per cent, solutions of acetic acid, in which 

 the eggs were immersed for three hours or more and afterwards stained 

 with Beale's carmine. Sections were made of eggs hardened in chro- 

 mic acid. 



U. Van Beneden's method of treating the ova of the rabbit. — For killing 

 and hardening a 1 per cent, solution of osmic acid was used, when the 

 eggs were transferred to MilUer'' s Jitiid for two or three days, washed? 

 and then mounted in glycerine. 



Brass's method of Idlling Amoebiform Protozoa. — In order to cause these 

 organisms to become comj^aratively quiet he recommends feeding them 

 with pulverized organic matter; they are then very slowly killed on the 

 slide by the use of the following solution, and while under observation 

 beneath the cover-glass : 



Chromic acid 1 jiart. 



Platinuui chloride 1 " 



Acetic acid 1 " 



Water, 400 to 1,000 parts. 



This solution, he claims, will kill monera and amoeba} without alter- 

 ing their organization. Osmic acid, he asserts, i)roduces dendritic ap- 

 pearances in the plasma of such organisms which are abnormal to them. 

 With this re-agent he has obtained evidence of a nuclear body in some 

 of the Monera. 



Brass also thinks that turpentine and i)arafiin, when used to saturate 

 an object to fit it to be cut into sections, also produces abnormal altera 

 tions in the tissues, and he recommends treating a tissue which is to be 



