SECTION TWO 



This is best seen in those parts of the cells where the granules 

 are fewer and not overlapping. The diameter of the rings is 

 approximately twice that of the dots. 



Notes: 



(a) The authors concluded from previous work of theirs, pub- 

 lished in 1956,* that each lipofuscin granule in human neurons is 

 built up of several concentric layers, which react differently to 

 the several staining methods which they applied. The technique 

 described above was developed for the purpose of revealing the 

 layered structure of the lipofuscin granules. 



(b) Histochemical work carried out by Shanklin & Issidorides 

 (1959)1 suggested the presence of free amino and carboxyl 

 groups, cystine, unsaturated fats, protein-bound SH and SS 

 groups and thereby supported the authors' view that these 

 granules represent either a lipoprotein or a proteolipid complex. 



(c) Reference should be made to the original paper (Nassar, 

 Issidorides & Shanklin, i960) for more detailed information and 

 photomicrographs . 



References : 



Nassar, T. K., Issidorides, M. & Shanklin, W. M. (i960). 

 Nassar, T. K. & Shanklin, W. M. (1951). 



* D'Angelo, C, Issidorides, M. & Shanklin, W. M. (1956). 

 t Shanklin, W. M. & Issidorides, M. (1959). 



SILVER NITRATE - COPPER SULPHATE - GOLD 



CHLORIDE 



For nerve fibres of Planarians 



Solutions required: 



A. Formalin, 40% formaldehyde .. 10 ml. 



Alcohol, 95% . . . . . . 45 ml. 



Glacial acetic acid . . . . . . 2 ml. 



*B. Copper sulphate (CUSO4, 5H2O), 

 10% aqueous 



C. Silver nitrate, 1% aqueous 



D. Pyrogallol, 1% aqueous 



417 



