An American text-book of physiology . Fig. 146 —^-Z), showing the pliylogcnetic development of mature nerve-cells in a series of ver-tebrates; a-e, the ontogenetic development of growing cells in a typical mammal; in both cases onlypyramidal cells from the cerebrum are .shown; .1, frog; i;, lizard; ; ; a, neuroblast withoutdendrons; 6, commencing dendrons; c, dendrons further developed; d, first ajjpearance of collateralbranches; e, further development of collaterals and dendrons (from S. Ram6n y Cajal). cells shown in Figure 146. Plere, from a pyramidal body {D) there arise anumber
An American text-book of physiology . Fig. 146 —^-Z), showing the pliylogcnetic development of mature nerve-cells in a series of ver-tebrates; a-e, the ontogenetic development of growing cells in a typical mammal; in both cases onlypyramidal cells from the cerebrum are .shown; .1, frog; i;, lizard; ; ; a, neuroblast withoutdendrons; 6, commencing dendrons; c, dendrons further developed; d, first ajjpearance of collateralbranches; e, further development of collaterals and dendrons (from S. Ram6n y Cajal). cells shown in Figure 146. Plere, from a pyramidal body {D) there arise anumber of , while from the lower portion of the cell the neuron growsout and branches. In the other type the neuron alone grows out. Its branches. Fig. 147.—Spinal ganglion of an embryo duck ; composed of dineuric nerve-cells (van Gehuchten). are but two in number and both are medullated. They pass in opposite direc-tions and in this type there are no dendrons. To understand the arrangementin these cases, recourse must be had to the facts of development. The second
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Keywords: ., bookautho, bookcentury1800, bookdecade1890, booksubjectphysiology
