THE METHOD OF SECTION-CUTTING WITH SOME 

 IMPROVEMENTS. 



By R. von Lendenfeld, Ph.D. 



It is a well-known fact that the structure of many organs of 

 plants and animals cannot be investigated without getting a direct 

 insight into the interior. It is easy enough to place a small 

 portion of the interior of any organ under the microscope, but it 

 is impossible in that way to ascertain the mutual position of parts. 

 To enable the observer to study them under the microscope and in 

 sufficient connection with other parts, so that their position can 

 be defined, there is only one method, that of section cutting. 



Organs of plants and a few hard parts of animals can be cut as 

 they are. It is advantageous to jikce such in a slit made in a 

 cork and cut them together with the adjacent cork with a sharp 

 razor. In cutting sections of plants, which are damp, it is 

 necessary to wet the razor so that the section, when cut, can 

 immediately be immersed in water and so prevented from drying 

 and shriveling up. 



Soft animal parts must be hardened. Any one of the methods 

 described in my paper on the preservation of tender marine 

 animals (proceedings of the Linnean Society of New South 

 Wales, Vol. IX.) can be used. The result will in every case be 

 that the hardened organ will be preserved in strong spirits, with 

 which it will also be saturated. The other methods of cutting 

 with the hand, and hardening and embedding simultaneously, and 

 the freezing method, do not seem to. yield such good results as the 

 one to be described below. 



Brothers Hertwig (Das Nervensystem und die Sinnesorgane 

 der Medusen) have made use of the former of these two methods. 

 They placed the specimen, after it had been treated with osmic 

 acid and stained with alum-carmin in a solution of gum-glycerine, 



