Section IV 

 BOTANY 



By E. C. Barton-Wright, M.Sc. 



Formerly Lecturer in Plant Physiology in University of Glasgow, 

 and Lecturer in Botany in University of London, King's 

 College, now Chief Assistant for Research in Virus Diseases 

 of the Potato at the Scottish Society for Research in Plant 

 Breeding, Corstorphine, Edinburgh. 



THE GOLGI APPARATUS 



Till within recent times the Golgi apparatus, first discovered 

 in 1898 by Golgi in the Purkinje cells of the barn owl's 

 brain, was not convincingly shown to be present in plant cells. 

 Definite evidence is now, however, forthcoming to show that the 

 Golgi apparatus is also present in plant cells. Bo wen has described 

 in the male heads of Polytrichum commune, P. juniperinum, P. 

 filiferum, in the root tips and growing points of Equisetum 

 arvense, and also in the root tips of Vicia faba, Pisum sativum and 

 other plants by the osmic acid impregnation method, certain 

 bodies which he has named " osmiophilic platelets^ These 

 platelets are suspended in the hyaloplasm, and are never found 

 within the vacuoles. They are disc-shaped and composed of osmio- 

 philic material. A large number of such discs occur in each cell, 

 though the number per cell varies enormously. They are relatively 

 small in size, though size variation is exhibited. During mitosis 

 there appears to be no orientation or division of the platelets, and 

 it is apparently due to chance that an equal distribution leads to 

 an approximately equal number of these bodies appearing in each 

 daughter cell. The method of division of the platelets was not 

 discovered, but possibly fragmentation may play a part. Bowen 

 definitely advanced the opinion that these osmiophilic platelets 



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