236 ROBERT S. ELLIS 



After embedding, the sections were cut on a rotary microtome 

 at 25 iJL, fixed to the shde with Meyer's albumen, and stained with 

 carbol-thionine and eosin. Better results are sometimes secured 

 with the cerebella of infants if Delafield's haematoxylin and 

 Orange G are used instead. Care must be taken that the 

 sections be not treated with absolute alcohol, as this dissolves 

 the parlodion. Equal parts of absolute alcohol and chloroform 

 may, however, be safely used (King, '10). 



The most satisfactory fiber preparations from old formol 

 material were secured by Bielschowsky's pyradine method. With 

 a modification of this the pericellular basket fibers have been 

 clearly shown in cerebella that had been in formol for thirteen 



Fig. 2 Section through a hemisphere of the human cerebellum in the plane 

 shown in figure 1. The designations are explained on page 237. 



years. If the pyradine is not thoroughly washed out before 

 putting into silver, and a weak solution of silver nitrate, 0.5 

 to 0.75 per cent, is used and changed frequentlj^, the fibers will 

 be impregnated with silver in one or two days. The sections 

 are then treated as usual. These fiber preparations give valuable 

 assistance in determining the character and causes of the 

 deficiency in cells. 



After staining, the sections on the slide were measured and 

 the measurements recorded on the cards with the original 

 measurements of the blocks as cut from the cerebellum at the 

 time of weighing. From these two measurements the percentage 

 of shrinkage is calculated. This will be referred to later. 



