148 bulletin: museum of comparative zoology. 



polarity of the ciliary-ganglion cells of mammals. In a later paper 

 (Retzius, '94, '94°) he confirmed his former observations by the aid of the 

 Golgi process. Using the latter method, Kolliker ('94) and Michel ('94) 

 obtained like results, and showed, furthermore, that the ganglion cells 

 are surrounded by pericellular baskets of nerve fibrils. These pericel- 

 lular baskets have also been demonstrated, and proved to be intracap- 

 sular, by the -niethylen-blue introrvitam stain (Huber, '97). Inasmuch 

 as all these conditions are characteristic of the cells of sympathetic gan- 

 glia, the investigators cited above are unanimous in declaring the mam- 

 malian ciliary ganglion to be sympathetic in nature. 



On the other hand, Schwalbe ('79), a " partisan ardent," to quote 

 Jegorow, of the cerebro-spinal character of the ciliary ganglion, found in 

 the ciliary ganglion of the sheep and calf unipolar cells, such as are char- 

 acteristic of cerebro-spiual ganglia. The crudeness of Schwalbe's methods, 

 however, leaves his results open to question. D'Erchia ('94) discovered 

 among the numerous multipolar cells of the cat's ciliary ganglion a few 

 bipolar cells. Such cells were seen in both the cat and dog by Holtz- 

 manu ('96), who, furthermore, found the comparatively small ciliary 

 ganglion of the rabbit to be composed mainly, if liot wholly, of cells of 

 the cerebro-spinal type, many being bipolar. Jegbrovi' ('86-87) figures, 

 in a colored plate, spinal, sympathetic and ciliary ganglion cells of the 

 cat, prepared by Boukhaloff according to a special differential method. 

 The cells from the spinal and ciliary ganglia present the same appear- 

 ance, whereas the sympathetic cells differ in staining qualities from the 

 others. It is interesting to compare with these figures those given by 

 His, Jun. ('91) of the same three kinds of ganglion cells taken from an 

 embryo cat. Cells from the ciliary and from a sympathetic ganglion 

 closely resemble each other, being small and unipolar. Those from the 

 vagus ganglion (which belongs to the cerebro-spinal ' series) are, on the 

 contrary, larger and bipolar in character. 



Haller ('98) believes that the conditions which obtain in the central 

 nervous system of the dog-fish and trout point to the cerebro-spinal 

 character of the representatives of ciliary-ganglion cells found in these 

 fishes. Golgi preparations of the mid-brain show, in addition to oculo- 

 motor neuraxons proceeding centrifugally from ganglion cells in motor 

 niduli, other oculomotor neuraxons, which have no direct connection 

 with central ganglion cells. These neuraxons he regards as centripetal 

 processes from ganglion cells on the oculomotor nerve (i. e., ciliary gan- 

 glion cells). Such cells are accordingly to be looked upon as homologous 

 with spinal-ganglion cells. 



