. Journal of comparative neurology. e cells ofthe mushroom bodies are all of the same size and are among thesmallest cells of the brain (fig. 3, E). They have a round oroval nucleus and so small an enveloping layer of cytoplasm thatit cannot be distinguished, even with the immersion lens, exceptat the distal end where the axon is given off. The chromatinmasses of the nucleus are all about the same size, forming a BRAIN OF THE WHITE ANT 567 peculiar characteristic pattern by which these cells may berecognized. Although the nerve cells are of similar size throughout themushroom bodies, they are
. Journal of comparative neurology. e cells ofthe mushroom bodies are all of the same size and are among thesmallest cells of the brain (fig. 3, E). They have a round oroval nucleus and so small an enveloping layer of cytoplasm thatit cannot be distinguished, even with the immersion lens, exceptat the distal end where the axon is given off. The chromatinmasses of the nucleus are all about the same size, forming a BRAIN OF THE WHITE ANT 567 peculiar characteristic pattern by which these cells may berecognized. Although the nerve cells are of similar size throughout themushroom bodies, they are differentiated into groups, or zones,according to their position. In the center of each cup or calyx,as seen in section (fig. 4), lies an oval mass of cells, /, which ishomologous in position with the central oval mass of large cellsfound in the bees, Jonescu (09), and in the ants, Pietschker (11),Thompson (12), and which I have termed Group I. On eachside of Group I, are broad wedge-shaped masses of cells (fig. 4, III II I II, Fig. 4 Diairram of a mushroom body, showing the nerve cell layer flividedinto groups, the calyces, and tho bos^inning of the stalk. /, cell group I; //, cellgroup II; ///, cell group III; gl., glia cells. //), which occupy most of the dorsal surface of each lobe andwhose inner margins overlap and enclose the central group masses, which appear separate in sections, form a con-tinuous zone if seen in surface view, and are homologous withGroup II of ants. Again, in each lobe, on each side of Group IIlie smaller masses of cells which form the lateral surfaces of thelobes (fig. 4, ///). There are only three, instead of four, of thesecell masses, because the inner lateral surfaces of the two lobesare in contact and their cells are continuous. These groups areequivalent in position to Groups III and IV of the ants. b. The fibrous core of the mushroom bodies. The cups or calycesof the inner and outer lobes of the mushroom bodies are com-posed (1) of
Size: 1541px × 1620px
Photo credit: © The Reading Room / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookauthorw, bookcentury1900, bookdecade1910, booksubjectmedicine
