CANALICL'LAR APPARATUS OF ANIMAL CELI.S. iS; 



'I In- hi-tory of the intracellular canalicular apparatus, con- 



n-d apart fn.ni the positive impregnations of Golgi and his 



follourr-. I.'-- ins with the discovery by Holmgren ('99) of endo- 



cellular net- of juice-canals in nerve cells which he said was 



exhibited particularly well in preparations made from ral>l>it 



tissui s. Almo-t at the same time Nelis ('99) described, in nerve 



ill- tixed in -ublimate or osmic acid and stained in iron-lia-ma- 



uliar coil-like bands to which he gave the name 



t spin " the nature of which, however, remained 



to him fully ob-cure. 



h ml publication (Holmgren, '99, 2) Holmgren described 



in . n ater d- tail the canalicular apparatus in the spinal ganglion 

 cell- of ill. rabbit, fixed in picric acid-sublimate and stained with 

 toluidi IK- blue and erythrosin. Hi- found in these cells nnler- 

 atel\ Inn- i anal- of fairly uniform calil>er which, anastomo-ing 

 ly, loriiu-il a ! airly dense network. The latter extended in 

 ' at- nmd the nucleus but often was found at one pole of the 

 inn Iru-. more rarely at both |w>lcs. Here and there he found 

 ihe-e i anal- communicating with pericellular canals, and at tl 

 point- In \\. ( - able to make out a distinct wall staining with 

 er\ thro-iii. Hi ~scd the opinion that the canals were of 



Kmphatic n, nun \\ithout however stating \\hether they were of 

 extracellular or int racellulur origin. 



In i^o'i ^indnit l.a ('99) also described the canals in the pro- 

 topla-m of ih. ganglion cells of the trigeminus of Petromyzon 



and al.-o in tin -pinal ganglion cells, in the nerve cells of the 

 medulla obloii-aia and the cells of Reissner of the same animal. 

 II. explained tl.. n of the canals as due to the union of a 



t"\\ ot \aciiolt--. . ; iid Kiid that while many of the canals had 

 -month contour-. \ t t in others might easily l)e seen the constit- 

 uent \aciiole- from \\hich they had arisen. In a foot-note In- 

 remarked that IK- had not found in his objects the connection 

 \\iih extrai ellnlar -trncturcs descril)ed by Holmgren, although 

 h. admitted that the canals opened on the surface into tin peri- 

 i rllnlar -p. 



In a series "f papers dating from 1899 Holmgren has described 

 the n -nits of hi.- in\e-iigations on this topic, covering a wide 

 range of material including not only nerve cells, but cells from 



