1) The branches of the cranial nerves can be identified from the developmental stage of the Streeter's horizon XVI
2) Before this identification of the branches begins to prolong the chorda tympani in the horizon XIV, N. petr. major in the horizon XV from N. facialis with ganglion geniculi.
3) Chorda tympani reaches mandibular arch in the horizon XIV, but it does not unifie with N. mandibularis. The unification of the chorda tympani with the lingual nerve may be established in the horizon XVI. The ganglion submandibulare appears soon after this unification in the earlier stage of the horizon XVII
4) In the developmental stage of the human embryo, in which the gangl. submandibulare is distinct, there appears a vague accumulation of the cell nuclei along the outer side of the greater petrosal nerve. The latter projects from the geniculate ganglion in the earlier developmental stage of the horizon XV and reaches the outer side of the internal carotid artery in the horizon XVI, then it prolonges forward to the maxillar nerve. The vague accumulation of the cell nuclei along the outer side of the greater petrosal nerve continues lateral and a little caudal to the medial sides of the maxillary and mandibular nerves. The ganglion pterygopalatinum and oticum become distinct in the later stage of the horizon XVII.
5) The ganglion ciliare begins to appear first at the later stage of the horizon XVII.
6) The cells of the ganglion submandibulare may be in the main conducted from the chorda tympani, the pterygomandibulare and oticum from the greater petrosal nerve, the ciliare from the oculomotor nerve.
7) The apperance of the minor petrosal nerve is so late that it comes definite first in the developmental stage of the horizon XVIII.
8) The differentiation of the muscle tissue begins at the stage of the horizon XVII, but the individual muscles are not distinct in this beginning, they begin to appear individually in the next horizon XVIII
9) At the developing stage of the horizon XVIII are the M. obl. bulbi sup. and rect. bulbi lat. distinct, while those muscles innervated by the oculomotor nerve remain as muscle mass. They appear individually first in 22mm long embryo except M. levat. palp. sup.
10) M. levator palp. sup. differentiates considerably later, as it begins to differentiate in our 35mm long embryo.
11) The branches of the nasociliar nerve, n. ethm. post. and ant., n. infratrochl. become distinct topographically in our 27mm and 35mm long embryos.
12) Neither anastomosis between N. lacrimalis and zygomaticus, nor lacrimal gland appears in our 35mm long embryo.
13) In 27mm long specimen appear two osseous maxillar and mandibular plates, while in 35mm long one except these two premaxillare, goniale, frontale, temp. squama and palate.
14) M. tensor tympani and stapedialis begin to differentiate in 22mm long specimen.
15) In 27mm long specimen M. tensor veli palatini becomes distinct from. M. pterygoid. medialis, M. pterygoid lat. from the temporal muscle, in 35mm long one begins to differentiate the M. levator veli palatini.

View full abstract