278 Scientific Proceedings, Royal DMin Society. 



at the end of the nucleus near the axon-hilloek (fig. 5), where, as already 

 remarked, the rods are few and unusually small. This perinuclear zone is not 

 seen "intra vitam," nor is it shown by any of the other techniques employed. 

 The zoning is similar to that described by one of the authors (J. B. G.) in the 

 oocytes of Saccocirrus prepared by Da Pano's method. 



In many of the neurones, in which the Golgi apparatus is in process of 

 fragmentation and spreading around the nucleus, dark zones, similar to those 

 around the nuclei of the larger cells, can be observed around each rod or group 

 of rods (figs. 2-4). This appears to indicate that the Golgi rods, not the nucleus, 

 as suggested in the case of Saccocirrus, are connected with their formation. 



In material fixed in Petrunkewitsch 's fluid and stained by Scott's 

 heematoxylin-eosin method (see BoUes Lee, 1922), the cj^oplasm of the neurone 

 is seen to be mainly basophil, with the excejjtion of the axon, which is oxyphil. 

 In medium-sized neurones, however, a juxta-nuclear oxyphil cloud appears. It 

 seems possible that this cloud is connected with the argentophil clouds described 

 in silver preparation, but this question is more fully dealt with by one of the 

 authors in a separate paper (P. W. R. B., 2). 



VIII. — Holmgren's Canals. 



Canals, similar to those originally described by Holmgren, are present in the 

 neurones of Helix, and were observed in many of our preparations. They are 

 of considerable length and sometimes branched (fig. 8), thus in no way resembling 

 the Golgi rods, as seen in our most thoroughly impregnated material. We are 

 not prepared, in this case, to affirm or deny the extra-cellular connection of these 

 canals, but in some neurones they were so related to processes of the sub- 

 capsular cells that they might be interpreted as continuous with them. 



IX. — On the Visibility of the Golgi Apparatus op Genital Cells 



''intra vitam." 



If the ovotestis of Helix be teased out "intra vitam" and examined in its 

 own lymph without staining, the nebenkei-n batonettes of the sperm cells of all 

 stages can be seen clearly. The apparatus is also visible while in the eccentric 

 position in the young oocytes, but, as it scatters in growth, gradually it becomes 

 indistinguishable. These observations support those from fixed material, in 

 which the nebenkern elements alter in cliemical constitution during dispersal 

 through the cytoplasm. This chemical change is accompanied by a change in 

 refractivity, which tends to make them invisible "intra vitam," although they 

 are still freely demonstrable by the osmic and silver nitrate techniques. 



The fact that in most cells the Golgi elements are invisible ' ' intra vitam ' ' has 

 been urged as evidence that in fixed preparations the so-called Golgi apparatus 

 is merely an artifact. That this argument is not convincing may easily be 

 shown, for, in the first place, the micro-chemical methods used for demonstrating 

 the Golgi apparatus reveal the latter both in cells in which the Golgi elements 

 are visible "intra vitam" (e.g. snail spermatocytes), and in cells in which the 

 Golgi elements are not visible "intra vitam" (e.g. snail neurones). 



Moreover, we have instanced the case of snaU oocytes where, in the young 

 cells, the apparatus is visible "intra vitam," but, as the yolk begins to form, the 

 apparatus undergoes certain chemical changes, and is then no longer visible, but 

 is still easily demonstrable after fixation. 



X. — Discussion. 

 Prom the time of its 'discovery the Golgi apparatus of the nerve cell of 

 mammals was recognised as a branching network, each element tending to 



